Logical Reasoning: Examples

Traditional talk therapy, in which a patient with a psychological disorder discusses it with a trained therapist, produces chemical changes in the brain. These changes seem to correspond to improvements in certain aspects of the patient's behavior. Thus, physicians will eventually be able to treat such patients as effectively through pharmacological intervention in the brain's neurochemistry as through the lengthy intermediary of traditional talk therapy. Which of the following is an assumption on which the argument depends? A. All neurochemical changes produce corresponding psychological changes. B. Improvements in a patient's behavior produced by talk therapy occur only through chemical changes in the brain's neurochemistry. C. Talk therapy has not been effective at bringing about psychological change. D. If chemical changes in the brain's neurochemistry correspond to improvements in patient behavior, then psychological and neuroscience will eventually become indistinguishable. E. Direct intervention in the brain's neurochemistry is likely to become a less expensive way of treating psychological disorders than is traditional talk therapy.

A. Incorrect. Fails the negation test: not all neurochemical changes produce corresponding psychological changes. We only require certain neurochemical changes to produce specific psychological changes. B. Correct. Passes the negation test:

In the paintings by seventeenth century Dutch artist Vermeer, we find several recurrent items: a satin jacket, a certain Turkish carpet, and wooden chairs. These reappearing objects might seem to evince a dearth of props. Yet we know that many of the props Vermeer used were expensive. Thus, while we might speculate about exactly why Vermeer worked with a small number of familiar objects, it was clearly not for lack of props that the recurrent objects were used. The conclusion follows logically if which one of the following is assumed? A. Vermeer often borrowed the expensive props he represented in his paintings. B. The props that recurrent in Vermeer's paintings were always available to him. C. The satin jacket and wooden chairs that reoccur in the paintings were owned by Vermeer's sister. D. The several recurrent items that appeared in Vermeer's paintings had special sentiment of importance for him. E. If a dearth of props accounted for the recurrent objects in Vermeer's paintings, then we would not see expensive props in any of them.

Argument Core: expensive props --> recurrent props not due to a lack of props. Assumption: because he owns expensive props, Vermeer must have had access to many more props. A. Incorrect. Weakens argument. If V had borrowed expensive props, then he may have experienced a lack of props. B. Incorrect. Unrelated / out of scope. No connection between cost and scarcity. C. Incorrect. Weakens argument. If V had borrowed expensive props, then he may have experienced a lack of props. D. Incorrect. Tempting, because it offers a potential explanation for recurrent use rather than a lack of props. However, it does not sufficiently fill the gap between expensive props and a lack of props. E. Correct. Recurrent props d2 a lack of props --> -expensive props. In other words, expensive props --> recurrent props not d2 a lack of props.

Florist: Some people like to have green carnations on St. Patrick's Day. But flowers that are naturally green are extremely rare. Thus, it is very difficult for plant breeders to produce green carnations. Before St. P's Dah, then, it is wise for florists to stock up on white carnations, which are fairly inexpensive and quite easy to dye green. Overall conclusion? A. It is a good idea for florists to stock up on white carnations before St. P's day. B. Flowers that are naturally green are very rare. C. There are some people who like to have green carnations on St. P's Day. D. White carnations are fairly inexpensive and can be easily dyed green. E. It is very difficult to breed green carnations

CONCLUSION A. MC B. Premise C. Premise D. Premise E. An implied premise

Geographer: Because tropical storms require heat an moisture, they form especially over ocean surfaces of at least 26 degrees Celsius, ocean temperatures that global warming would encourage. For this reason, many early discussions of global warming predicted that it would cause more frequent and intense tropical storms. But recent research shows that this prediction is unlikely to be born out. Other factors, such as instabilities in wind flow, are likely to counteract global warming's effects on tropical storm development. Which one of the following most accurately expresses the conclusion drawn in the geographer's argument? B. Contrary to early discussions, global warming is not the only factor affecting the frequency and intensity of tropical storms. C. If global warming were reversed, tropical storms would be less frequent and less intense. E. Global warming probably will not produce more frequent and intense tropical storms.

CONCLUSION Heat and moisture --> storms GW --> heat and moisture Many predictions that GW --> frequent and intense storms HOWEVER P: other actors such as instabilities in wind flow likely counteract GW's effects on storms. MC: the prediction that GW --> frequent and intense storms is unlikely B. Detail creep. "Early discussions" never claimed that GW was the only factor affecting storms, but rather that GW would impact the development of the storms. C. Illegal reversal. E. Correct

A controversial program rewards prison inmates who behave particularly well in prison by giving them the chance to receive free cosmetic plastic surgery performed by medical students. The program is obviously morally questionable, both in its assumptions about what inmates might want and in its use of the prison population to train future surgeons. Putting these moral issues aside, however, the surgery clearly has a powerful effect rehabilitative effect, as is shown by the fact that, among recipients of the surgery, the proportion who are convicted of new crimes committed after release is only half that for the entire prison population as a whole. A flaw in the reasoning of the passage is that it A. Allows moral issues to be a consideration in presenting evidence about the matter of fact. B. Dismisses moral considerations on the grounds that only matters of fact are relevant. C. Labels the program as "controversial" instead of discussing the issues that give rise to the controversy. D. Asserts that the rehabilitation of criminals is not a moral issue. E. Relies on evidence drawn from a sample that there is reason to believe is unrepresentative.

D is false. We are evaluating logic and reasoning, not what the author "should have done." E is correct. The sample only includes inmates with particularly good behavior.

The best jazz singers use their voices much as horn players use their instruments. The great Billie thought of her singing voice as a horn, reshaping melody and words to increase their impact. Conversely, jazz horn players achieve their distinctive sounds by emulating the spontaneous twists and turns of an impassioned voice. So jazz consists largely of voice-like horns and horn-like voices. Which one of the following must accurately describes the role played in the argument by the claim that best jazz singers use their voices much as horn players use their instruments? A. It is the argument's main conclusion and is supported by another statement, which is itself supported by another statement. B. It is the argument's only conclusion, and each of the other statements in the argument is used to support it. C. It is a statement for which some evidence is provided and which in turn is used to provide support for the argument's main conclusion. D. It is a statement for which no evidence is provided but which itself is used to support the argument's only conclusion. E. it is a statement used to support a conclusion that in turn is used to support the argument's main conclusion.

DETERMINE THE FUNCTION IC, premise for IC, premise for MC, MC C is correct. D is incorrect because evidence is provided.

Economists reason that price gouging--increasing the price of goods when no alternative seller is available--is efficient because it allocates goods to people whose willingness to pay more shows that they really need those goods. But willingness to pay is not proportional to need. In the real world, some people simply cannot pay as much as others. As a result, a price increase will allocate goods to the people with the most money, not to those with the most need. Which one describes the role played by the claim that willingness to pay is not proportional to need? A. It disputes one explanation in order to make way for an alternative explanation. E. It denies a claim that the argument takes to be assumed in the reasoning that it rejects.

DETERMINE THE FUNCTION P: price gouging allocates goods to people who demonstrate willingness to pay and therefore need for the good. P: willingness to pay is not proportional to need IC: this theory of price gouging is false. MC: price increase allocates goods to wealthy. A. Incorrect. The claim questions why price gouging is efficient. For this answer to be correct ("in order to make way for an alternative explanation"), the author would then have to go on to offer an alternative explanation for why price gouging is efficient, which does not occur. E. Correct. The economists assume that willingness to pay = need, and assumption with which the author takes issue. And, in rejecting the assumption, the author rejects the conclusion, as well.

Columnist: it has been noted that attending a live music performance is a richer experience than listening to recorded music. Some say that this is merely because we do not see the performers when we listen to live music. However, there must be some other reason, for there is relatively little difference between listening to someone read a story over the radio and listening to someone in the same room read a story. Which one of the following most accurately expresses the role played in the argument by the observation that attending a live musical performance is a richer experience than is listening to recorded music? A. It is what the columnist's argument purports to show. B. It is a reason given for the claim that the columnist's argument is attempting to undermine. C. It is what the columnist's argument purports to explain. D. It is what the columnist's argument purports to refute. E. It is what the position that the columnist tries to undermine is purported to explain.

DETERMINE THE FUNCTION PREMISE: Some say that attending a live music performance is richer than listening to recorded music because we see the performer. However, there is little difference between listening to someone read a story over the radio and listening to someone in the same room read a story. CONCLUSION: There must be some reason beyond the performer's presence for why attending a live music performance is richer than listening to recorded music. A. Incorrect. The author challenges an alternative explanation for this idea. B. Incorrect. It is not the reason but rather the claim whose premise the author attempts to undermine. C. Close. Misses that the author also challenges an alternative explanation for this idea. D. Incorrect. The author does not refute this claim itself, but rather a presented premise for the claim E. Correct.

Editorial: the town would not need to spend as much as it does on removing trash if all town residents sorted their household garbage. However, while telling residents that they must sort their garbage would get some of them to do so, many would resent the order and refuse to comply. The current voluntary system, then, is to be preferred, because it costs about as much as a nonvoluntary system would and it does not engender nearly as much resentment. The contention that the town would not need to spend as much as it does on removing trash if all town residents sorted their household garbage plays which one of the following roles in the editorial's argument? A. It is a claim that the editorial is trying to show is false. B. It is a fact granted by the editorials that lends some support to an alternative to the practice that the editorial defends as preferable.

DETERMINE THE FUNCTION PREMISES: NV --> decreases costs. NV --> noncompliance and resentment V --> costs same as NV V --> -resentment CONCLUSION: V > NV A. False. Editorial accepts this as true. B. True. Claim supports NV, which is an alternative to the preferable V system.

Ethicist: the penalties for drunk driving are far more severe when the drunk driver accidentally injures people than when no one is injured. Moral responsibility for an action depends solely on the intentions underlying the action and not on the action's results. Therefore, legal responsibility, depending as it does in at least some cases on factors other than the agent's intentions, is different from moral responsibility. The claim that penalties for drunk driving are far more severe when the drunk driver accidentally injures people than when no one is injured plays which one of the following roles in the ethicist's argument? A. It is a premise offered in support of the claim that legal responsibility for an action is based solely on features of the action that are generally unintended by the agent. B. It is offered as an illustration of the claim that the criteria of legal responsibility for an action include but are not the same as those for moral responsibility. C. It is offered as an illustration of the claim that people may be held morally responsible for an action for which they are not legally responsible. D. It is a premise offered in support of the claim that legal responsibility depends in at least some cases on factors other than the agent's intentions. E. It is a premise offered in support of the claim that moral responsibility depends solely on the intentions underlying the action and not on the action's result.

DETERMINE THE FUNCTION Premise: MR depends on intention only. Penalties for drunk driving are more severe in cases of more harm. Conclusion: Legal responsibility differs from MR. A. False. This claim is not made. B. False. This claim is not made; the conclusion is concerned with the difference between LR and MR rather than their shared criteria. C. False. This claim is not made. D. Correct. E. False. This premise is not used to support this claim.

Edgar: Some of the pumps supplying water to our region have been ordered to shut down in order to protect a species of small fish. But it is absurd to inconvenience thousands of people for the sake of something so inconsequential. Rafaela: You're missing the point. The threat to that fish species is a sign of a very serious threat to our water supply. The dialogue provides the most support for the claim that E and R disagree over: A. Shutting down the pumps will actually inconvenience a large number of people. B. The survival of the fish species is the only reason for shutting down the pumps. C. Species of small fish are inconsequential. D. The order to shut down the pumps was legal. E. Shutting down the pumps will be sufficient to protect the fish species.

DISAGREEMENT A. Incorrect. E: agree R: ? B. Correct. E: agree R: disagree C. Incorrect. E: agree R: ? D. Incorrect. E: ? R: ? E. Incorrect. E: ? R: ?

In a study, pairs of trained dogs were placed side by side and given a command such as "sit." After both obeyed the command, one dog was given a treat while its partner was given no reward at all. Over time, the dogs who went unrewarded began to disobey the command. This shows that dogs have an aversion to being treated unfairly. Which one of the following would be most useful to know in order to evaluate the argument? A. Were dogs who were accustomed to receiving regular rewards prior to the study more inclined to obey the command? B. Is there a decline in obedience if rewards are withheld from both dogs in the pair? C. Were the dogs who received treats in one trial ever used as dogs that did not receive treats in other trials? D. Were there any cases in which the dog who was given a reward became more inclined to obey the command? E. How many repetitions were required before the unrewarded dogs began to disobey the command?

EVALUATE A. Out of scope. Since we know the dogs both obeyed the command in at least some instances, their inclination was overcome by the time the study started to hand out treats. B. Bingo. In this case, the dogs are treated fairly. If there's a decline in obedience, it's likely that the lack of a treat (instead of unfairness) was what drove the misbehavior. If there's no decline, then fairness is looking more likely. C. Out of scope. Since each trial is a self-contained test between two dogs, prior situations would, at most, explain obedience at the beginning. It doesn't help evaluate why obedience went down for a non-treat-receiving dog over time. D. Half scope. If the answer to this question were, "Yes," that might suggest the treats were the driver and not fairness. However, if the answer is, "No," then it doesn't help us at all, so this question isn't necessarily useful. E. Out of scope. The number of repetitions doesn't affect fairness since we don't know how quickly a dog can evaluate fairness.

A recent poll showed that almost half of the city's residents believe that Major Walker is guilty of ethics violations. Surprisingly, however, 52% of those surveyed judged Walker's performance as mayor to be good or excellent, which is no lower than it was before anyone accused him of ethics violations. Which of the following, if true, most helps to explain the surprising fact stated above? A. Almost all of the people who believed that Walker is guilty of ethics had thought, even before he was accused of those violations. B. In the time since Walker was accused of ethics violations, there has been an increase in the percentage of city residents who judge the performance of Walker's opponents to be good or excellent. C. About a fifth of those polled did not know that Walker had been accused of ethics violations. D. Walker is currently up for re-election, and anti corruption groups in the city have expressed support for Walker's opponent. E. Walker has defended himself against the accusations by arguing that the alleged ethics violations were the result of honest mistakes by this staff members.

FLAW A proposes that the mayor's performance is poor and unethical are correlated. This is an explanation for the apparent discrepancy. This is correct.

Council member: I recommend that the abandoned shoe factory be used as the municipal emergency shelter. Some council members assert that the courthouse would be a better shelter site, but they have provided no evidence of this. Thus, the shoe factory would be a better shelter site. A questionable technique used in the council member's argument is that of A. Asserting that a lack of evidence against a view is proof that the view is correct. B. Accepting a claim simply because advocates of an opposing claim have not adequately defended their view.

FLAW A. is false because the council members never present evidence against the author's view. Rather, the council members present evidence--or lack thereof--for their own view B is correct.

Cotrell, at best, is able to write magazine articles of average quality. The most compelling pieces of evidence for this are those few of the numerous articles submitted by Cotrell that are superior, since, Cotrell, who is incapable of writing an article that is better than average, must obviously have plagiarized the superior ones. The argument is most vulnerable to the criticism that A. It simply ignores the existence of potential counter evidence. B. It generalizes from atypical occurrences. C. It presupposes what it seeks to establish. D. It relies on the judgement of experts in a matter to which their expertise is irrelevant. E. It infers limits on ability from a few isolated lapses in performance.

FLAW Circular reasoning; presupposes what it seeks to establish P: Cotrell is incapable of writing a better than average article IC: Cotrell must have plagiarized his few superior articles MC: Cotrell can write only low to average quality articles A does not ignore the presence of counter-evidence demonstrating superior performance. Rather, the author misinterprets. B is incorrect. There are "atypical occurrences" mentioned, but rather than generalize from these occurrences, the author attempts to prove the opposite of what they would imply C is correct.

Political theorist: the chief foundations of all governments are the legal system and the police force; and as there cannot be a good legal system where the police are not paid well, it follows that where the police are paid well, there will be a good legal system. The reasoning in the argument is not sound because it fails to establish that A. Many governments with bad legal systems have poorly paid police forces. B. Bad governments with good legal systems must have poorly paid police forces. C. A well-paid police force cannot be effective without a good legal system. D. A well-paid police force is sufficient to guarantee a good legal system. E. Some bad governments have good legal systems.

FLAW Conditional logic P: -police paid well —> -legal system C: police paid well —> legal system D

Occultist: the issue of whether astrology is a science is easily settled: it is both science and an art. The scientific components are the complicated mathematics and the astronomical knowledge needed to create an astrological chart. The art is the synthesis of a multitude of factors and symbols into a coherent statement of their relevance to an individual. The reasoning in the occultist's argument is most vulnerable to criticism on the grounds that the argument: A. Presumes, without providing justification, that any science must involve complicated mathematics. B. Incorrectly infers that a practice is a science from the fact that the practice has some scientific components. C. Denies the possibility that astrology involves components that are neither artistic nor scientific. D. Incorrectly infers that astronomical knowledge is scinetific merely from the fact that such knowledge is needed to create an astrological chart. E. Presumes, without providing justification, that any art must involve the synthesis of a multitude of factors and symbols.

FLAW Here, it is important to ask "does the argument even do this?" This argument concludes that astrology is a science (and an art). Why? Premise 1: The scientific components and complicated maths and the astronomical knowledge. Premise 2: The art portion is of many symbols and factors into a coherent statement of their relevance to an individual. What truly being said here is that those components of art and science are sufficient to make it an art or science. For example, for the science portion it assumes that because of: - complicated math - astronomical knowledge Then therefore, it's a science. A. This answer choice says science ---> complicated math, but the argument claims complicated math --> science. B. Correct. C. The argument does not do this. D. "Merely because" is incorrect. Argument never states "since astronomical knowledge is needed to create an astrological chart, therefore astronomical knowledge is scientific." Rather, it infers that astronomical knowledge is scientific because it is a known component of science. Furthermore, it never really presumes its scientific FOR any reason, it simply just accepts that it is scientific. E. This answer choice says art --> synthesis, but the argument claims synthesis --> art.

The coach of the Eagles used a computer analysis to determine the best combinations of players for games. The analysis revealed that the team has lost only when Jennifer was not playing. Although no computer was needed to discover that information, this sort of information is valuable, and in this case it confirms that Jennifer's presence in the game will ensure that the eagles win. The argument above is most vulnerable to criticism on the grounds that it A. Infers from the fact that a certain factor is sufficient for a result that the absence of that factor is necessary for the opposite result. D. Presumes, without providing justification, that occurrences that have coincided in the past must continue to coincide.

FLAW Lost —> -Jennifer Jennifer —> -lost A. Incorrect. Argument in fact does the opposite by inferring that a certain factor (Jennifer playing) is necessary for a condition, and that the lack of that factor (-Jennifer playing) is sufficient for the absence of that condition. D. Correct. Identifies the temporal flaw.

Commentator: Many social critics claim that contemporary journalists' cynical tendency to look for selfish motives behind the seemingly altruistic actions of powerful people undermines out society's wellbeing by convincing people that success is invariably associated with greed and mendacity. But the critics' claim is absurd. The cynicism of contemporary journalists cannot be a contributing factor to the undermining of our society's wellbeing, for journalists have always been cynics. Today's journalists are, if anything, more restrained than their predecessors. The reasoning in the commentator's argument is most vulnerable to criticism on the grounds that it overlooks the possibility that A. Widespread cynicism is beneficial to the well-being of society. B. Cynicism about the motives of powerful people increases with the amount of information one has about them. C. The work of contemporary journalists reflects a cynicism that is not really genuine. D. Any description of human behavior portrays it as selfish. E. Cynicism of this type on part of journalists has always had a negative effect on the well-being of society.

FLAW P: journalists have always been cynics P: today's journalists are more restrained C: cynicism is not a contributing factor to undermining society's wellbeing A: cynicism from journalists have never undermined society's wellbeing A. Incorrect. If anything, this possibility would strengthen the argument. B. Incorrect. No clear link between knowing information about powerful people and undermining society's wellbeing. C. Incorrect. Unsupported and not relevant. If anything, this possibility would strengthen the argument. D. Incorrect. Tempting, but "any human behavior" is broad and we cannot determine that selfish portrayals will undermine society's wellbeing. E. Correct. Addresses the assumption.

R: C's claims that her car's trunk popped open because the car hit a pothole. Yet, she also acknowledged that the trunk in that car had popped open on several other occasions, and that on none of those other occasions had the car hit a pothole. Therefore, C mistakenly attributed the trunk's popping open to the car having hit a pothole. The reasoning in R's argument is most vulnerable to the criticism that the argument A. Fails to consider the possibility that the trunks of other cars may pop open when those cars hit potholes. B. Fails to consider the possibility that potholes can have negative effects on a car's engine. C. Presumes, without justification, that if one event causes another, then it cannot also cause a third event. D. Fails to consider the possibility that one type of event can be caused in many different ways. E. Presumes the truth of the claim that it is trying to establish.

FLAW R: since X is caused by Y, then it cannot be caused by Z. Causation flaw. C. Incorrect. A tempting answer because it identifies a causation flaw. However, the stimulus is concerned with how the event was caused rather than what the event causes. D. Correct

Counselor: Those who believe that criticism should be gentle rather than harsh should consider the following: change requires a motive, and criticism that is unpleasant provides a motive. Since harsh criticism is unpleasant, harsh criticism provides a motive. Therefore, only harsh criticism will cause the person criticized to change. What is the flaw? A. Infers that something that is sufficient to provide a motive is necessary to provide a motive. B. Fails to address the possibility that in some cases the primary goal of criticism is something other than bringing about change in the person criticized. C. Takes for granted that everyone who is motivated to change will change. D. Confuses a motive for doing something with a motive for avoiding something. E. Takes the refutation of an argument to be sufficient to show that the argument's conclusion is false.

FLAW Stimulus: P: Change -requires-> motive Unpleasant criticism —> motive IC: Harsh criticism —> unpleasant criticism —> motive MC: Change-requires-> harsh criticism Assumption: motive -requires-> harsh criticism A. Correct. The author assumes that since harsh criticism is sufficient for motive, it is also necessary for motive. This is a conditional logic flaw.

A museum director, in order to finance expensive new acquisitions, discretely sold some paintings by major artists. All of them were paintings that the directly privately considered inferior. Critics roundly condemned the sale, charging that the museum had lost first rate pieces, thereby violating its duty as a trustee of art for future generations. A few months after being sold by the museum, those paintings were resold, in an otherwise stagnant art market, at two or three tones the price paid to the museum. Clearly, the prices settled the issue, since they demonstrate the correctness of the critics' evaluation. The reasoning in the argument is vulnerable to the criticism that the argument does which of the following? A. It concludes that a certain opinion is correct on the grounds that it help by more people than hold the opposing view. B. It rejects the judgement of experts... C. It rejects a proven means of accomplishing an objective without offering an alternative means of accomplishing that objective. D. It bases a firm conclusion about a state of affairs in the present on somewhat speculative claims about a future state of affairs. E. It bases its conclusion on facts that could, in the given situation, have resulted from causes other than presupposed by the argument.

FLAW Trick; causation flaw, not a fact v opinion flaw Premise: Deemed inferior —> sold cheaper Deemed superior —> sold at a more expensive price Conclusion: Sold at more expensive price —> proof that deemed superior A is tempting but does not occur. The conclusion does not determine that the art is superior because many people think so, but rather because it sold as a higher price. E is correct. There are numerous other factors that may have influenced why the paintings resold for the higher price (ex: influence of the critics' opinion)

Advertisement: a leading economist has determined that among people who used computers at their place of employment last year, those who also owned portable computers earned 25% more on average than those who did not. It is obvious from this that owning a laptop computer led to a high paying job. Which of the following identifies a reasoning error in the argument? A. It attempts to support a sweeping generalization on the basis of information about only a small number of individuals. B. It's conclusion merely restates a claim made earlier in the argument. C. It concludes that one thing was caused by another although the evidence given is consistent with the first thing's having caused the second. D. It offers information as support for a conclusion when that information actually shows that the conclusion is false. E. It uncritically projects currently existing trends indefinitely into the future.

FLAW Trick; causation flaw; potential relationship in the opposite direction D is correct. The evidence more strongly supports the conclusion that high include is responsible for owning a laptop computer.

M, despite his generally poor appetite, thoroughly enjoyed the three meals he ate at the hotel, but, unfortunately, after each meal he became ill. The first time he ate an extra large pizza with peppers. The second time, he took full advantage of the all you can eat shrimp and peppers special. The third time, he had two giant meatballs with peppers. Since the only food all three meals had in common was peppers, M concluded that it was solely due to peppers that he became ill. M's reasoning is most vulnerable to which of the following criticisms? A. He draws his conclusions on the basis of too few meals that were consumed at the hotel. B. He posits a causal relationship without ascertaining that the presumed cause preceded the presumed effect. C. He allows his desire to continue dining at the hotel to bias his conclusion. D. He fails to establish that everyone at the hotel also became ill after eating peppers. E. He overlooks the fact that all three meals consumed was, for him, an unusually large amount of food.

FLAW Trick; not a causation flaw A. The argument does not do this. It does not extrapolate beyond the three meals. B. The argument does not do this. Becoming ill did not come before eating the peppers. E. Correct. It is given that M generally has a poor appetite.

Some paleontologists believe that certain species of dinosaurs guarded their young in protective nests long after the young hatched. As evidence, they cite the discovery of fossilized hadrosaur babies and adolescents in carefully designed nests. But similar nests for hatchlings and adolescents are constructed by modern crocodiles, even though crocodiles guard their young only for a very brief time after they hatch. Hence, ______. Which one of the following most logically completes the argument? A. Paleontologists who believe that hadrosaurs guarded their young long before the young hatched have no evidence to support this belief. B. We will never be able to know the extent to which hadrosaurs guarded their young. C. Hadrosaurs guarded their young for at most very brief periods after hatching. D. It is unclear whether what we learn about hadrosaurs from their fossilized remains tell us anything about other dinosaurs. E. The construction of nests for hatchlings and adolescents is not strong evidence for the paleontologist's belief.

INFERENCE A. False. Unsupported; evidence is provided B. False. Language too extreme C. False. Out of scope; unsupported by stimulus D. False. Out of scope. We care about learning about hadrosaurs from crocodiles, not other dinosaurs from hadrosaurs. E. Correct

These days, drug companies and health professionals alike are focusing their attention on cholesterol in the blood. The more cholesterol we have in our blood, the higher the risk that we shall die of a heart attack. The issue is pertinent since heart disease kills more North Americans every year than any other single cause. At least three factors--smoking, drinking, and exercise--can each influence levels of cholesterol in the blood. Which one of the following can be properly concluded from the passage? A. If a person has low blood cholesterol, then that person's risk of fatal heart disease is low. B. Smoking in moderation can etail as great a risk of fatal heart disease as does heavy smoking. C. A high-cholesterol diet is the principal cause of death in North America. D. The only way that smoking increases one's risk of fatal heart disease is by influencing the levels of cholesterol in the blood. E. the risk of fatal heart disease can be altered by certain changes in lifestyle.

INFERENCE A. Illegal negation, might not be true B. Scope and degree (stimulus says "influence" and answer choice has "entail") C. Detail creep (diet replaces cholesterol in the blood) D. Degree, may not be the "only" way E. Correct

There are two kinds of horror stories: those that describe a mad scientist's experiments and those that describe a monstrous beast. In some horror stories about monstrous beasts, the monster symbolizes a psychological disturbance in the protagonist. Horror stories about mad scientists, on the other hand, typically express the author's feeling that scientific knowledge alone is not enough to guide human endeavor. However, despite these differences, both kinds of horror stories share two features: they describe violations of the laws of nature and they are intended to produce dread in the reader. If the statements above are true, which one of the following would also have to be true? A. All descriptions of monstrous beasts describe violations of the laws of nature. B. Any story that describes a violation of a law of nature is intended to invoke dread in the reader. C. Horror stories of any kind usually describe characters who are psychologically disturbed. D. Most stories about mad scientists express the author's anti-scientific views. E. Some stories that employ symbolism describe violations of the laws of nature.

INFERENCE A. Incorrect. Degree; too extreme. B. Incorrect. Degree. Scope; we do not know about "any story," only horror stories. C. Incorrect. Degree; "usually" = more than half, yet we only know that some horror stories with monsters describe characters who are psychologically disturbed. D. Incorrect. Author merely states that science alone is insufficient. "Anti-scientific" is too extreme. E. Correct.

In response to several bacterial infections traced to its apple juice, McElligott now flash pasteurizes its apple juice by quickly heating and immediately rechilling it. Intensive pasteurization, in which juice is heated for an hour, eliminates bacteria more effectively than does any other method, but is likely to destroy the original flavor. However, because McElligott's citrus juices have not been linked to any bacterial infections, they remain unpasteurized. The statements above, if true, provide the most support for which of the following claims? A. McElligott's citrus juices contain fewer infectious bacteria than do citrus juices produced from other companies. B. McElligott's apple juice is less likely to contain infectious bacteria than are McElligott's citrus juices. C. McElligott's citrus juices retain more of the juices' original flavor than do any pasteurized citrus juices. D. The most effective method for eliminating bacteria from juice is also the method most likely to destroy the flavor. E. Apple juice that undergoes intensive pasteurization is less likely than McElligott's apple juice is to contain bacteria.

INFERENCE A. Incorrect. We are only given information that compares citrus juices to apple juice within M company. B. Incorrect. Contradicts the premises that M apple juices have been linked to bacterial outbreaks while M citrus juices have not. C. Incorrect. We only know that intensive pasteurization is likely to decrease original flavor, but we don't know how original flavor initially compares among these groups. D. Incorrect. Degree; we know that intensive pasteurization is a method that eliminates bacteria and destroys flavor, but "most" is too extreme. E. Correct. Intensive pasteurization kills more bacteria than flash pasteurization.

In a vast ocean region, phosphorus levels have doubled in the past few decades due to agricultural runoff pouring out of a large river nearby. The phosphorus stimulates the growth of plankton near the ocean surface. Decaying plankton fall to the ocean floor, where bacteria devour them, consuming oxygen in the process. Due to the resulting oxygen depletion, few fish can survive in this region. Which one of the following can be properly inferred from the information above? A. The agricultural runoff pouring out of the river contributes to the growth of plankton near the ocean surface. B. Before phosphorus levels doubled in the ocean region, most fish were able to survive in that region. C. If agricultural runoff ceased pouring out of the river, there would be no bacteria on the ocean floor devouring decaying plankton. E. The amount of oxygen in a body of water is in general inversely proportional to the level of phosphorus in that body of water.

INFERENCE Ag runoff --> increase in P --> increase in plankton --> decrease in O2 --> decrease in fish A. True. Inference links ag runoff --> increase in plankton B. False. Unsupported generalization. C. False. Illegal negation. -Ag runoff --> -decrease in O2 D. False. Detail creep and term shift; even if phosphorus has doubled, we cannot know that agricultural runoff has doubled. E. False. Answer choice states "in general," yet the stimulus only describes one area. Stimulus only states certain circumstances (two data points) where O2 has decreased while phosphorus increased; we cannot describe this as inversely proportion.

An instructor presented two paintings to the class. She said that the first had hung in prestigious museums but the second was produced by an unknown amateur. Each student was asked which painter was better. Everyone selected the first. The instructor later presented the same two paintings in the same order to a different class. This time she said that the first was produced by an known amateur but the second had hung n prestigious museums. In this class, everyone said that the second painting was better. The statements above, if true, most strongly support which one of the following? C. East of the students would like most of the paintings in any prestigious museum. D. In judging the paintings, some of the students were affected by what they had been told about the history of the paintings. E. Had the instructor presented the paintings without telling the students anything about them, almost all of the students would have judged them to be roughly equal in artistic worth.

INFERENCE C. Incorrect. Out of scope and extreme language: "each" / every student, "most" paintings, "any" museum. D. Correct. Must be true E. Incorrect. "Equal artistic worth" is a specific and unsupported claim.

Interior decorator: All coffeehouses and restaurants are public places. Most well-designed public places feature artwork. But if a public place is uncomfortable, it is not well designed, and all comfortable public places have spacious interiors. If all of the interior decorator's statements are true, then which of the following must be true? A. Any restaurant that has a spacious interior is comfortable. B. Most public places that feature artwork are well designed. C. Most coffee places that are well-designed feature artwork. D. Any well-designed coffeehouse or restaurant has a spacious interior. E. Any coffeehouse that has a spacious interior is a well-designed public place.

INFERENCE Coffee house and restaurant --> public place Most well-designed public place have artwork -Comfortable public place --> -well designed Comfortable public place --> spacious interior Inferences Well designed --> comfortable --> spacious interior A. Spacious interior --> comfortable. Illegal reversal; incorrect B. Artwork --> well-designed. Illegal reversal; incorrect C. Well-designed --> artwork. However, it is possible that coffee places are a form of public places that does not feature artwork D. Well-designed --> spacious interior. Correct E. Spacious interior --> well-designed. Illegal reversal; incorrect

Everyone in B's neighborhood is permitted to swim at Barton Pool at some time during each day that it is open. No children under the age of 6 are permitted to swim at Barton Pool between noon and 5 pm. From 5 pm until closing, Barton Pool is reserved for adults only. If all the sentences above are true, then which of the following must be true? A. Few children under the age of 6 live in B's neighborhood. B. If B's next-door neighbor has a child under 6, then B pool is open before noon. C. If most children who swim in Barton Pool swim in the afternoon, then the pool is generally less crowded after 5 pm. D. On days when Barton Pool is open, at least some children swim there in the afternoon. E. Any child swimming in Barton Pool before 5 pm must be breaking Barton Pool rules.

INFERENCE Everyone in the neighborhood is permitted to swim. Noon and 5 --> -children under 6, 6-18, adults 5 until closing --> adults only, - children under 6, -6-18 Prediction: when do children under 6 swim? A. Unsupported. B. Since everyone is permitted to swim, and children under 6 are not allowed to swim between noon and closing, then the pool must be open before noon. C. We only know about the adults who swim after 5, so our knowledge about children does not apply. D. Unsupported. It is possible that all children in the neighborhood are below 6 and thus swimming before the afternoon. E. "Any child" is not specific to "children under 6" in the stimulus.

Quasars--celestial objects so far away that their light takes at least 500 million years to reach Earth--have been seen since 1963. For anything that far away to appear from Earth the way quasars do, it would have to burn steadily at a rate that produces more light than 90 billion suns would produce. But nothing that burns at a rate that produces that much light cold exist for more than 100 million years. If the statements above are true, which one of the following must be true on the basis of them? A. Instruments in use before 1963 were not sensitive enough to permit light to be seen. B. Light from quasars first began reaching Earth in 1963 C. Anything that from Earth appears as bright as a quasar does must produce more light than would be produced by 90 billion suns. D. Nothing that is as far from earth as quasars are can continue to exist for more than 100 million years. E. No quasar that has ever been seen from Earth exists any longer.

INFERENCE FACTS: Quasars have been seen since 1963. Their light takes 500 million years to reach us. For anything that far away to send light to us it would have to burn with the brightness of 90 billion suns (wow.) Anything that burns that bright will burn out after about 100 million years. ANALYSIS: We can conclude that any Quasar we see has already burned out. It takes 500 million years for their light to reach us, but they burn out after only 100 million years. A. Incorrect. Detail creep; the stimulus does not mention that we need instruments to see the quasars B. Incorrect. We don't know. The light might have been there before but we never noticed. C. Incorrect. Degree. Detail creep; does not specify that those objects are so far away that their light takes 500 million years to reach Earth D. Incorrect. Degree. Detail creep; does not specify that those objects can be seen from Earth. E. Correct. By the time we see the light, the quasar has burned out

Teachers are effective only when they help their students become independent learners. Yet not until teachers have the power to make decisions in their own classrooms can they enable their students to make their own decisions. Students' capability to make their own decisions is essential to their becoming independent learners. Therefore, if teachers are to be effective, they must have the power to make decisions in their own classrooms. According to the argument, each of the following could be true of teachers who have enabled their students to make their own decisions EXCEPT: A. Their students have not become independent learners. B. They are not effective teachers. C. They are effective teachers. D. They have the power to make decisions in their own classrooms. E. They do not have the power to make decisions in their own classrooms.

INFERENCE Premises: Teachers effective —> students become independent learners -Teachers make decisions —> -students make decisions Students become independent learners—> students make decisions Conclusion: Teachers effective —> teachers make decisions Assumption: Teacher effective —> students become independent learners —> students make decisions —> teachers make decisions Inferences given "students make decisions": Students make decisions —> teachers make decisions A. Incorrect. Could be true. Students making decisions is not sufficient to guarantee that students become independent learners. B and C. Incorrect. Could be true. D. Incorrect. Must be true. Students make decisions —> teachers make decisions. E. Correct. Must be false. Students make decisions —> teachers make decisions.

The solidity of bridge piers built on pilings depends largely on how deep the pilings were driven. Prior to 1700, pilings were driven "to refusal," that is, to the point at which they refused to go any deeper. In a 1588 inquiry into the solidity of piers for Venice's Rialto Bridge, it was determined that the bridge's building, Antonio, had met the contemporary standard for refusal: he had caused the pilings to be driven until additional penetration into the group was not greater than two inches after 24 hammer blows. Which one of the following can properly be inferred from the passage? A. The Bridge was built on unsafe pilings. B. The standard of refusal was not sufficient to ensure safety. C. Antonio's standard of refusal was less strict than that of other bridge builders of his day. D. After 1588, no bridges were built on pilings that were driven to the point of refusal. E. It is possible that the pilings of the Rialto Bridge could have been driven deeper even after the standard of refusal had been met.

INFERENCE Prior to 1700 Standard (PS): "Refusal" is met when "the point at which they (pilings) refused to go any deeper." Contemporary Standard (CS) "Refusal" has been met when "additional penetration into the ground was no greater than two inches after twenty-four hammer blows." C. Incorrect. No information is provided regarding the standard in 1588. D. Incorrect. Out of scope. E. Correct. The Bridge met the CS but could be driven 2 inches deeper.

The purpose of a general theory of art is to explain every aesthetic feature that is found in any of the arts. Premodern general theories of art, however, focused primarily on painting and sculpture. Every premodern general theory of art, even those that succeed as theories of painting and sculpture, fails to explain some aesthetic feature of music. The statements above, if true, most strongly support which one of the following? A. Any general theory of art that explains the aesthetic features of painting also explains those of sculpture. B. A general theory of art that explains every aesthetic feature of music will achieve its purpose. C. Any theory of art that focuses primarily on sculpture and painting cannot explain every aesthetic feature of music. D. No premodern general theory of art achieves its purpose unless music is not art. E. No premodern general theory of art explains any aesthetic features of music that are not shared with painting and sculpture.

INFERENCE Purpose of GTA is to explain EVERY aesthetic feature of ANY art Premodern GTA focused on painting and sculpture EVERY premodern GTA failed to explain SOME aesthetic feature of music. A. Incorrect. It is possible for GTA to explain painting but not sculpture or vice versa (and not achieve their purpose). B. Incorrect. A GTA will not achieve its purpose if it explains music but not painting and sculpture. C. Incorrect. "Any" is too extreme; it includes non-premodern GTA D. Correct. E. Incorrect. Detail creep: "any aesthetic features of music" differs from "some aesthetic features of music"

When uncontrollable factors such as lack of rain cause farmers' wheat crops to fail, fertilization and seed dealers, as well as truckers and mechanics, lose business, and fuel suppliers are unable to sell enough fuel to make a profit. Which one the following claims follows logically from the information above? A. If several businesses that sell to farmers do not prosper, it is because farming itself is not prospering. B. If rainfall is below average, those businesses that profit from farmers' purchases tend to lose money. C. Farmers are not responsible for the consequences of a wheat crops failing if the failing has been affected by lack of rain. D. A country's dependence on agriculture can lead to major economic crises. E. The consequences of a drought are not restricted to the drought's impact on farm productivity.

INFERENCE When no rain leads to no wheat → farmer suffers → businesses suffer A. False. Illegal reversal. There are other reasons why a business may fail B. False. Degree (not all loss of rain causes outcome. It is only when loss of rain leads to loss of wheat that outcome occurs) and detail creep (lack of rain / no rain v. below average, unable to make a profit / potentially breaking even v. losing money, the listed businesses v. all businesses that profit) C. False. Detail Creep (responsibility never addressed) and Scope (entirely not responsible?) D. False. Generalization E. True.

Most people invest in the stock market without doing any research of their own. Some of these people rely solely on their broker's advice, whereas some others make decisions based merely on hunches. Other people do some research of their own, but just as often rely only on their broker or on hunches. Only a few do their own research before investing. Nonetheless, a majority of investors in the stock market make a profit. If the statements in the passage are true, which one of the following must also be true? A. Some people who make a profit on their investments do so without doing any research of their own. B. Most people who invest in the stock market either rely solely on their broker or make decisions based merely on hunches. C. Some people who do investment research on their own, while just as often relying on their broker or on hunches, make a profit in the stock market. D. Most people who invest in the stock market without doing any research o their own make a profit.

INFERENCE Most: no research, advise, hunch Others: research, advise, hunch Few: research B. Incorrect. Detail creep: stimulus only claims that most do not research, not that most rely solely on advise or hunches. C. Incorrect. The stimulus states that a majority makes a profit. It is possibility that those who make a profit are composed entirely of those who do not research. D. Incorrect. "Most" is too extreme. It is possible that only some who do not research make a profit. E. Most people who rely solely on their broker rather than on hunches make a profit in the stock market.

Some eloquent speakers impress their audiences with the vividness and clarify of the messages conveyed. Speakers who resort to obscenity, however, are not genuinely eloquent, so none of these speakers impress their audiences. The flawed reasoning in which one of the following is most similar to that in the argument above? B. There are authors who write one page a day and produce one book a year. Serious authors, however, do not write one page per day, so some authors who write one book a year are not serious. E. Sculptors sometimes produce significant works of art

MATCH THE FLAW Eloquent + impress -(some)- vivid/clear Obscenity --> not eloquent Obscenity --> -impress B. Quantifier mismatch; conclusion is about "some authors" E. Correct. Sculptors -(some)- significant works of art Musicians --> -sculptors Musicians --> -significant Not a perfect match, but the closest match. For this question, we could eliminate all wrong answers based on quantifiers alone. If the quantifiers are a part of the flaw, they have to show up in the answer choices.

Had the party's economic theories been sound and had it succeeded in implementing its program, the inflation rate would have lessened considerably. But because the inflation rate actually increased, the party's economic theories were far off mark. The flawed reasoning in which one of the following arguments most closely resembles the flawed reasoning in the argument above? A. If the people who inhabited the valley for so long had been invaded, or if there had been a dramatic climatic change, there would have been changes in the valley's architecture. But architecture in the valley remained the same throughout their stay. Thus, the valley people must not have been invaded at any point during their stay. B. Many people fear that if the opposition party wins the election and keeps its promise to cut wages dramatically, workers in key industries will strike. But because the workers have promised not to strike, these workers must think the party will not keep its promise of a dramatic wage cut. C. If the company had succeeded in selling its subsidiaries and used the cash to purchase the new patent, its stock price would have doubled in the last two years. But the price of the stock did not increase in that time. Thus, the company must have failed to sell its subsidiaries.

MATCH THE FLAW Flaw in conditional logic; the author attempts to argue by contrapositive but confuses the "and" and "or" rules Given: A + B --> C Contrapositive: -C --> -A or -B -C. Therefore, -A (we cannot come to this conclusion. It is possible that -B is true instead) A. Incorrect. This conditional has "or", not "and." B. Tempting but incorrect. Temporal mismatch. The description of C is inconsistent: "workers have promised not to strike" v "workers will not strike." C. Correct.

If the majority of the residents of the apartment complex complain that their apartments are infested with ants, then the management of the complex will have to engage the services of an exterminator. But the majority of residents of the complex indicate that their apartments are virtually free of ants. Therefore, the management of the complex will not have to engage the services of an exterminator. Which one of the following arguments contains a pattern of flawed reasoning parallel to that contained in the argument above? A. A theater will be constructed in the fall if funds collected are at least sufficient to cover its cost. To date, the funds collected exceed the theater's cost, so the theater will be constructed in the fall. B. The number of flights operated by the airlines cannot be reduced unless the airlines can collect higher airfares. But people will not pay higher airfares, so it is not the case that the number of flights will be reduced. C. In order for the company to start the proposed building project, both the town council and the mayor must approve. Since the mayor has already approved, the building project will be started soon. D. Most employees will attend the company picnic if the entertainment committee is successful in getting a certain band to play at the picnic. But the band will be out of the country on the day of the picnic, so it is not true that most employees will attend. E. Either the school's principal or two-thirds of the parent council must approve a change in the school dress code in order for the code to be changed. Since the principal will not approve a change in the dress code, the code will not be changed

MATCH THE FLAW P1: complain --> hire P2: -complain C: -hire ILLEGAL NEGATION The correct answer will engage in this same flaw (illegal negation). A. Incorrect. Logically valid. Positive, not negative conclusion. P1: sufficient funds --> theater P2: sufficient funds C: theater B. Incorrect. Logically valid. P1: -higher fares --> -number reduced number reduced --> higher fares P2: -higher fares C: -number reduced C. Incorrect. Logically invalid, but not illegal negation. P1: town council approves + major approves —> construct P2: major approves C: construct D. Correct. Illegal negation. P1: band performs --> most employees attend P2: -band performs C: -most employees attend E. Incorrect. Contains a compound conditional (in addition to a flaw in interpreting the compound conditional) that is not described in the stimulus. P1: change code --> principal approves or 2/3 of the parent council approve P2: -principal approves C: -change code

The years of 1990 are all notable for the occurrence of both popular uprisings and near-maximum sunspot activities. During heavy sunspot activity, there is a sharp rise in positively charged ions in the air that people breathe, and positively charged ions are known to make people anxious and irritable. Therefore, it is likely that sunspot activity has actually been a factor in triggering popular uprisings. Which of the following exhibits a pattern of reasoning most similar to that in the passage? A. The ancient Greeks sometimes attempted to predict the outcome of future events by watching the flight patterns of birds. Since the events themselves often matched the predictions, the birds were probably responding to some factor that also influenced the events. B. M, S, and H are the city's three most powerful politicians, and all three graduated from Ridgeview High. Although Ridgeview High never had a reputation for excellence, it must have been a good school to have produced three such successful graduates. C. Unusually cold weather last December coincided with a rise in fuel prices. When it is cold, people use more fuel to keep warm; and when more fuel is used, prices rise. Therefore, if prices are high next winter, it will be the result of cold weather. D. The 30 healthiest people in a long-term medical study turned out to be the same 30 people whose regular diets included the most vegetables. Since specific substances in vegetables are known to help the body fight disease, vegetables should be a part of everyone's diet. E. Acme's most productive managers are consistently those who occupy the corner offices, which have more windows than other offices at Acme. Since people are more alert when they are exposed to abundant natural light, the greater productivity of these managers is probably at least in part due a result of their working in corner offices.

MATCH THE REASONING P1: A is correlated with B P2: Explanation of A C: A is likely a factor that causes B A. Incorrect. Conclusion matches. Premise type mismatch; it lacks the premise that explains A. B. Incorrect. Conclusion type mismatch; lacks causal language. C. Incorrect. Conclusion type and strength mismatch; conditional rather than causal language; extreme language. D. Incorrect. Conclusion type mismatch; normative rather than causal language. E. Correct.

To get the free dessert, one must order an entree and a salad. But anyone who orders either an E or a S can receive a free drink. Thus, anyone who is not eligible for a free drink is not eligible for a free dessert. The reasoning in the argument above is most similar to the reasoning in which of the following arguments? B. To be elected class president, one must be well liked and well known. Anyone who is well liked or well known has something better to do than to run for class president. Therefore, no one who has something better to do will run for class president. C. To grow good Azaleas, one needs soil that is both rich in humus and low in humidity. Anyone who has soil that is rich in humus or low in acidity can growth blueberries. So, anyone who cannot grow blueberries cannot grow azaleas.

MATCH THE REASONING Premises: Free dessert —> E + S E or S —> free drink Free desserts —> E + S —> free drink Conclusion: -free drink --> -E and - S --> -free dessert B. Incorrect. Erroneously concludes "elected pres" when it should conclude "-elected pres" P: Elected pres --> well liked and well known Well liked or well known —> something better to do something better to do Elected pres —> well liked and well known —> something better to do C: -Something better to do --> -well liked and -well known —> elected pres C. Correct P: Azaleas —> rich humus and low humidity Rich humus or low humidity —> blueberries Azaleas —> rich humus and low humidity —> blueberries C: -blueberries —> -rich humus and -low humidity —> -Azaleas

To cut costs, a high school modified its air-conditioning system to increase its efficiency. The modified system, however, caused the humidity in the school to decrease by 18%. 24 hours after the decrease in air humidity, a 25% increase in the number of visits to the school nurse was reported. This shows that a decrease in humidity can make people ill. The argument depends on assuming which of the following? A. At least some of the visits to the school nurse after the system was modified were due to illness. B. Most of the students at the high school suffered from the decrease in air humidity. C. It takes 24 hours after a person is infected with a virus for that person to exhibit symptoms. D. A decrease of 18 percent in air humidity causes an increase of 25% in one's probability of becoming ill. E. Modifying the air-conditioning system proved to be an ineffective way to cut costs.

NECESSARY ASSUMPTION A. Correct. Passes the negation test: "none of the visits to the school nurse after the system was modified were due to illness" C. Incorrect.

A transit company's bus drivers are evaluated by supervisors riding with each driver. Drivers complain that this affects their performance, but because the supervisor's presence affects every driver's performance, those drivers performing best with a supervisor aboard will likely also be the best drivers under normal conditions. Which of the following is an assumption on which the argument depends? A. There is no effective way of evaluating the bus drivers' performance without having supervisors ride with them. B. The supervisors are excellent judges of a bus drivers' performance. C. For most bus drivers, the presence of a supervisor makes their performance slightly worse than it otherwise would be. D. The bus drivers are each affected roughly the same way and to the same extent by the presence of the supervisor. E. The bus drivers themselves are able to deliver accurate assessments of their driving performance.

NECESSARY ASSUMPTION C is tempting. While this would suggest that bus drivers actually perform better in normal conditions, the conclusion is not that bus drivers will perform better than observed under supervision. Rather, the conclusion states that the best drivers under supervisor are also the best drivers under normal conditions. Additionally, it is not an assumption that the argument depends upon. D is correct. This assumption is necessary for the conclusion that the best drivers under supervision are also the best drivers under normal conditions.

It is popularly believed that a poem has whatever meaning is assigned to it by the reader. But object evaluation of poetry is possible only if this popular believe is false; for the aesthetic value of a poem cannot be discussed unless it is possible for at least two readers to agree on the correct interpretation of the poem. Assumption required by the argument? A. Only if they find the same meaning in a poem can two people each judge that it has aesthetic value. B. If two readers agree about the meaning of a given poem, that ensures that an objective evaluation of the poem can be made. C. Discussion of a poem is possible only if it is false that a prime has whatever meaning is assigned to it by the reader. D. A given people can be objectively evaluated only if the poem's aesthetic value can be discussed. E. Aesthetic evaluation of literature is best accomplished through discussion by more than 2 readers.

NECESSARY ASSUMPTION P: Discuss aesthetic value —> 2 readers agree on interpretation. C: Objective evaluation —> -reader assigns meaning A: Discussing aesthetic value is necessary for objective evaluation. A. Incorrect: restatement of premise: Discuss aesthetic value —> 2 readers agree. Furthermore, the stimulus is specific to discussing aesthetic value, not discussing if it has aesthetic value. B. Incorrect. 2 readers agree on interpretation —> objective evaluation, yet we are interested in demonstrating that discussing aesthetic value is relevant to objective evaluation. C. Incorrect. Discuss —> -reader assigns meaning. Does not address objective evaluation. Out of scope; we are concerned with aesthetic discussion, not all discussion. D. Objective evaluation —> discuss aesthetic evaluation. E. Incorrect. "Best" is out of scope.

Zoologist: Every domesticated large mammal species now in existence was domesticated thousands of years ago. Since those days, people undoubtedly tried innumerable times to domesticate each of the wild large mammal species that seemed worth domesticating. Clearly, therefore, most wild large mammal species in existence today either would be difficult to domesticate or would not be worth domesticating. The argument requires the assumption that: A. In spite of the difficulties encountered, at one time or another people have tried to domesticate each wild large mammal species. B. It is not much easier today to domesticate wild large mammal species than it was in the past. C. Not all of the large mammal species that were domesticated in the past are still in existence. D. The easier it is to domesticate a wild large mammal species, the more worthwhile it is to do so. E. Of all the domesticated large mammal species in existence today, the very first to be domesticated were the easiest to domesticate.

NECESSARY ASSUMPTION P: Early humans attempted to domesticate species that were worth domesticating. Current domestic species were domesticated thousands of years ago. In other words, earlier humans tested all "seemingly worthwhile" large mammals and filtered out the too-difficult ones C: Current wild large species either difficult to domesticate or not worth domesticating. A: If these worthwhile mammals were not domesticated, it was because they were too difficult to be domesticated. A. "Each" is too extreme. The stimulus states that humans only attempted to domesticate animals that appeared worth domesticating. B. Negation test: It is much easier today to domesticate wild large mammal species than it was in the past. When B is negated, the argument falls apart. Most wild large animals today may not be too difficult to domesticate. C is not necessary. It is TEMPTING because it is similar to the author's assumption that "all of the undomesticated large mammal species in existence today were in existence in the past". E is too extreme. It is not necessarily the case that the very first domesticated mammal was the easiest.

Only engineering is capable of analyzing the nature of a machine in terms of the successful working of the whole; physics and chemistry determine the material conditions necessary for this success, but cannot express the notion of purpose. Similarly, only physiology can analyze the nature of an organism in terms of organs' roles in the body's healthy functioning. Physics and chemistry cannot ascertain by themselves any of these operational principles. Which one of the following is an assumption required by the analogy? A. The functioning of the human organism is machine-like in nature. B. Physics and chemistry determine the material conditions required for good physiological functioning. C. The notion of purpose used by engineers to judge the success of machinery has an analogy in organisms D. Physiology as a science is largely independent of physics and chemistry. E. Biological processes are irreducible to mechanical or chemical processes.

NECESSARY ASSUMPTION Premises: The author gives an analogy to machines. In machines, physics and chemistry can't express the notion of the purpose of a machine, while engineering can. In an organism, physics and chemistry can't express operational principles. CONCLUSION: Physiology can; only physiology can determine how an organism works in terms of how organs play a role in a body's functioning. ANALYSIS: "The notion of purpose" was essential in the machine analogy. So in the case of the organism, the author must assume that there is something analogous to "purpose" which physics and chemistry also can't express. A. Incorrect. An analogy can still exist. B. Incorrect. Physiological functioning is not relevant to the discussion of machines. C. Correct. Purpose was the only factor mentioned which explained why physics and chemistry cannot analyze machines and engineering can. Thus, there must be an analogy to purpose for organisms to explain why physics and chemistry cannot analyze organisms while physiology can.

During the recent economic downturn, banks contributed to the decline by loaning less money. Prior to the downturn, regulatory standards for loanmaking by banks were tightened. Clearly, therefore, banks will lend more money if those standards are relaxed. The argument assumes that: A. The downturn did not cause a significant decrease in the total amount of money on deposit with banks, which is the source of funds for banks to lend. B. The imposition of the tighter regulatory standards was not a cause of the economic downturn. C. the reason for tightening the regulatory standards was not arbitrary. D. No economic downturn is accompanied by a significant decrease in the amount of money loaned out by banks to individual borrowers and to businesses. E. No relaxation of standards for loanmaking by banks would compensate for the effects of the downturn.

NECESSARY ASSUMPTION P: Increase in regulation --> less loaning --> economic downturn. C: Decrease in regulation --> more loaning A. Correct. Passes the negation test due to a detail creep: the downturn caused a significant decrease in funds for banks to lend; with this loss in funds, the bank cannot increase loanmaking. B. Incorrect. Weakens the argument. C. Incorrect. Fails the negation test; the motives behind the regulation are irrelevant. D. Incorrect. Passes the negation test: SOME economic downturns are accompanied by a significant decrease in the amount of money loaned out by banks to individual borrowers and to businesses; "some" does not destroy the argument. Furthermore, the argument specifies loaning to individual borrowers and businesses only, which does not mean that the bank can't still increase loanmaking overall. E. Incorrect. Does not address loanmaking after the relaxation.

Teacher to a student: You agree that it is bad to break promises. But when we speak to each other we all make an implicit promise to tell the truth, and lying is the breaking of that promise. So even if you promised Jeanne that you would tell me she is home sick, you should not tell me that, if you know that she is well. Which one of the following is an assumption on which the teacher's argument depends? A. Most people always tell the truth. B. It is sometimes better to act in a friend's best interests than to keep a promise to that friend. C. Breaking a promise leads to worse consequences than does telling a lie. D. Some implicit promises are worse to break than some explicit ones. E. One should never break a promise.

NECESSARY ASSUMPTION P: When we speak, we make an implicit promise to tell the truth. Bad to lie and break promises. C: Even if you promised to lie for your friend, if you know she is well, you should not say that she is not well. Assumption: The implicit promise to tell the truth is more important than the promise to lie. A. Incorrect. Out of scope. Addresses what individuals do rather than what individuals should do. Fails the negation test: "Half or fewer of people always tell the truth." B. Incorrect. Friend's best interest is unrelated to promise to tell the truth. C. False. The student has made two promises. Does not justify prioritizing one promise over another. Fails the negation test: "Breaking a promise does not lead to worse consequences than does telling a lie." This negation may help the argument, because it suggests that it is not worse to break a promise. D. Correct. Fails the negation test: "No implicit promises are worse to break than explicit ones." E. False. Does not justify prioritizing one promise over another. Fails the negation test: "One should sometimes break a promise." This negation actually supports the argument.

Braille is a method of producing text by means of raised dots that can be read by touch. A recent development in technology will allow flat computer screens to be made of a material that can be heated in patterns to replicate the patterns used in Braille. Since the thermal device will utilize the same symbol system as Braille, it follows that anyone who is accustomed to reading Braille can easily adapt to use this electronic system. Which one of the following is an assumption on which the conclusion depends? A. Braille is the only symbol system that can be readily adapted for use with the new thermal screen. B. Only people who currently use Braille as their sole medium for reading will have the capacity to adapt to the use of the thermal screen. C. People with tactile ability to discriminate symbols in Braille have an ability to discriminate similar patterns on a flat heated surface. D. Some symbol systems encode a piece of text by using dots that replicate the shape of letters of the alphabet. E. Eventually it will be impossible to train people to read Braille without first training them in the use of the thermal screen.

NECESSARY ASSUMPTION P: heated Braille use the same symbols as tactile Braille C: those who can read Braille will easily adapt to heated Braille. Assumption: tactile symbols = heated symbols A is not necessary for the argument. B is not necessary. C is necessary. Negation: people who discriminate tactile Braille can not discriminate heated Braille. The argument depends on this. D describes systems other than Braille and is out of scope. E supports the effectiveness of heated Braille but is out of scope and not necessary for the argument.

Recent medical and anthropological data show that prohibitions on the use of certain foods served important social, economic, and medical functions in ancient cultures. But these data cannot explain the origin of the prohibitions involved, since those who originally adopted and enforced them did not have access to the same data as modern researchers. Which one of the following is an assumption required by the argument? A. The origin of a food prohibition must be explained with reference to the understanding that the people who adopted and enforced the prohibition had. B. The social, economic, and medical problems of a society may lead to the adoption of contradictory food prohibition. C. D. The original purpose of a food prohibition is often forgotten a few generations after the prohibition is introduced. E. The people who originally adopted and enforced food prohibitions in ancient cultures generally had a nontechnical understanding of the medical functions of those prohibitions.

NECESSARY ASSUMPTION PREMISES: 1. Modern data shows that prohibitions had important social, economic, and medical roles. 2. Those who adopted and enforced prohibitions did not have the same access as modern researchers. CONCLUSION: Modern data cannot explain the origin of these prohibitions. A. Correct B. Unsupported; out of scope D. Out of scope. Forgetting is irrelevant to the reasoning why those who adopted and enforced prohibitions must have access to the same data as modern researchers in order to understand the origin of prohibitions. E. Out of scope. This detail about nontechnical understandings is irrelevant to the reasoning why those who adopted and enforced prohibitions must have access to the same data as modern researchers in order to understand the origin of prohibitions.

Ethicist: studies have documented the capacity of placebos to reduce pain in patients who believe that they are receiving beneficial drugs. Some doctors say that they administer placebos because medically effective treatment reinforced by the placebo effect sometimes helps patients recover more that treatment alone. But administering placebos is nonetheless ethically questionable, for even if a placebo benefits a patient, a doctor might, for example, have prescribed it just to give the patient satisfaction that something was done. The argument depends on which one of the following assumptions? A. A patient's psychological satisfaction is not a consideration for administering medical treatment. B. The motivation for administering a placebo can be relevant to the ethical justification for doing so. C. Medical treatment that relies on the placebo effect alone is ethically indefensible. D. The pain relief produced by the placebo effect justifies the deception involved in administering placebo. E. Administering placebo is not ethically justified if that treatment is not prescribed by a doctor.

NECESSARY ASSUMPTION P: placebo works as treatment; yet doctors may merely prescribe placebo to give patient satisfaction MC: ethically questionable A: prescribing placebos merely for patient satisfaction unethically outweighs benefits enough to make the practice ethically questionable A fails the negation test: a patient's psychological satisfaction is a consideration in administering medical treatment. Not necessary; actually boosts P that doctors merely prescribe placebos for patient satisfaction. Furthermore, "consideration" is too vague; does not address the concept of ethics. B satisfies with the negation test: the motivation for administering a placebo can not be relevant to the ethical justification for doing so; argument falls apart. C is not necessary. This language is too extreme, as the MC uses the word "questionable" and C uses the word "indefensible." Furthermore, the stimulus addresses placebo in conjunction with medically necessary treatments, not just placebo. D weakens the argument. E does not address the ethics of prescribing the placebo.

A large survey of scientists found that almost all accept Wang's Law, and almost all know the results of the Brown-Eisler Experiment. But those results together with wang's Law contradict the Minsk Hypothesis. Therefore, most of the scientists surveyed rejected the Minsk Hypothesis. The argument requires assuming which one of the following? A. The scientists surveyed are generally aware that the results of the Brown-Eisler Experiment contradict together with the Minsk Hypothesis. B. The scientists in the survey who know the results of the Brown-Eisler Experiment are exactly the

P: Scientists accept Wang's Law and know the results of the BE Experiment. P: These two contradict the M hypothesis C: Scientists must not believe the M hypo. Assumption: Scientists are aware of the contradiction. This A. Correct B. Degree is too strong. The argument doesn't require the two groups to overlap exactly, as long as the overlap accounts for most of the scientists.

During this record breaking heat wave, air conditioning use has overloaded the region's electric power grid, resulting in frequent power blackouts throughout the region. For this reason, residents haven been asked to cut back voluntarily on air conditioning in their homes. But even if this request is heeded, blackouts will probably occur unless the heat wave abates. Which of the following, if true, most helps to resolve the apparent discrepancy in the information above? A. Air conditioning is not the only significant drain on the electrical system in the area. B. Most air conditioning in the region is used to cool businesses and factories. C. Most air-conditioning systems could be made more energy efficient by implementing simple design modifications. D. Residents of the region are not likely to reduce their air conditioner use voluntarily during particularly hot weather. E. The heat wave is expected to abate in the near future.

PARADOX Heat wave and AC —> overload —> blackout However, -AC among RESIDENTS —> blackouts A is tempting. However, it is given that the heat wave and AC use are sufficient to cause blackouts. Other factors that cause blackouts should not disrupt this relationship. B describes the paradox. D is incorrect because the conclusion assumes that the request is satisfied.

If grain prices double then the average price of a loaf of bread will rise between 10 and 15 percent, whereas the price of grain-fed been will come close to doubling. Which one of the following would, if true, most contribute to an explanation of the phenomenon described above? A. Farmers engaged in very large-scale cattle production generally try to reduce the labor costs involved in the production and sale of beef. B. The wholesale price per pound of beef is approximately 10 times the wholesale price per pound of bread. C. The labor and marketing costs in producing and selling bread represent most of its cost, but the cost of feeding cattle represents most of the cost of producing beef. D. Only an insignificantly small proportion of the beef sold in retail markets is produced from cattle fed on grass rather than grain. E. The vast majority of retail grocery outlets purchase the bread they sell from small independent bakers but purchase the meat they sell from wholesale processing operations.

PARADOX Prediction: correct answer must explain why bread prices increase less than A. Incorrect. No comparison between the prices of bread and beef. B. Incorrect. Contradicted; suggests that the price of beef is directly proportional to the price of bread, rather than grain. C. Correct. Suggests that grain forms most of the cost of producing beef but only a small fraction of the cost of producing bread. Explains why price of beef would increase more than bread. D. Incorrect. No comparison between the prices of bread and beef. E. Incorrect. Irrelevant. Discusses where retailers buy their grain and beef but fails to discuss the costs associated with each product.

Tania: A good art critic is not fair in the ordinary sense; it is only about things that do not interest one that one can give a truly unbiased opinion. Since art is a passion, good criticism of art cannot be separated from emotion. Monique: Art is not simply passion. The best art critics passionately engage with the artwork, but render their criticism only after shredding all of their biases and consulting general principles of aesthetics. The dialogue most strongly supports the claim that T and M disagree about whether: A. Art is not simply a passion. B. Good art criticism is sometimes unbiased.

POINT OF DISAGREEMENT A. T believes that art is a passion, not necessarily that art is SIMPLY a passion. B. Correct. T believes that good criticism is biased.

Lutsina: Because futuristic science fiction does not need to represent current social realities, its writers can envisage radically new social arrangements. Thus, it has the potential to be a richer source of social criticism than conventional fiction Priscilla: That futuristic science fiction writers more skillfully envisage radically new technologies than new social arrangements shows how writers' imaginations are constrained by current realities. Because of this limitation, the most effective social criticism results from faithfully presenting the current social realities for critical examination, as happens in conventional fiction. L and P disagree with each other about whether: A. Some science fiction writers have succeeded in envisaging convincing, radically new social arrangements. C. Futuristic science fiction has more promise as a source of social criticism than does conventional fiction.

POINT OF DISAGREEMENT Lutsina: Premise: FSF does not need to represent current social realities --> FSF can show new social arrangements. MC: FSF does social criticism better than conventional fiction. Priscilla: Premise: FSF shows new tech better than new social arrangements. The best social criticism comes from showing current social realities MC: Conventional fiction does social criticism better than FSF. A. Detail creep. L and P do not disagree on whether FSF writers have succeeded. Rather, they disagree on the degree of success. Furthmore, answer choice generalizes to science fiction writers, while stimulus referus to FSF writers. C is correct.

A. In a well-functioning democracy, any bill that would benefit most people will be passed into law within a few years if it does not violate anyone's basic free rights. B. If a democracy is well functioning, then any bill that is opposed by influential people but favored by most other people will eventually pass into law. C. In a well-functioning democracy, a bill that is favored by most people will become law within a few years only if those who oppose it are not influential. D. Any bill passed into law in a well-functioning democracy will be favored by most people and be consistent with individuals' basic human rights. E. A bill that most people favor will be passed prompty into law in a well-functioning democracy if the bill does not violate anyone's basic human rights.

PREMISE 1) most people favor the bill 2) it doesn't violate basic human rights 3) adversely affected are influential 4) as a result, the bill will not be passed for many years, or never CONCLUSION Country is not a well-functioning democracy. PRINCIPLE: 1) if this situation above occurs --> no functioning democracy 2) in a functioning democracy --> this situation does not occur 3) in a functioning democracy --> if most people favor bill and the bill does not violate human rights, it will pass A. Incorrect. We are concerned with people who favor the bill. B. Incorrect. Misses the criterion of human rights. Additionally, "eventually" does not change from the situation above (where the "bill will not be passed for many years, or never) C. Incorrect. Misses the criterion of human rights. Furthermore, it states that if the opposition IS influential, a majority-favored bill would take a long time to pass. This is exactly the result in our stimulus. D. Incorrect. Reversal. In a functioning democracy --> if bill is passed, most people favor bill and the bill does not violate human rights. E. Correct.

A gift is not generous unless it is intended to benefit the recipient and is worth more than what is expected or customary in the situation; a gift is selfish if it is given to benefit the giver or less valuable than is customary Which one of the following judgments most closely conforms to the principle above? D. Olga gives her daughter a computer as a graduation gift. Since this is the gift that all children in Olga's family receive for graduation, it is not generous. E. Michael gave his nephew $50, more than he had ever given before. His nephew, however, lost the money. Therefore, Michael's gift was not generous because it did not benefit the recipient.

PRINCIPLE EXAMPLE -intended to benefit recipient + -worth more than expected --> -generous generous --> intended to benefit recipient generous --> worth more than expected intended to benefit giver --> selfish less valuable than customary --> selfish A. Incorrect. Principle does not discuss cost of gift; no cost --> selfish does not conform. B. Incorrect. Principle does not discuss harm. C. Incorrect. Unsupported application: intended to benefit gift giver --> generous D. Correct. -worth more than expected --> -generous CHECK THIS pg 405 of LR Strategy E. Incorrect. Detail creep: specifies that the gifts BENEFITS the recipient, but not that it is INTENDED to benefit the recipient.

Columnist: Taking a strong position on an issue makes one likely to misinterpret or ignore additional evidence that conflicts with one's stand. But in order to understand an issue fully, it is essential to consider such evidence impartially. Thus, it is best not to take a strong position on an issue unless one has already considered all important evidence conflicting with that position. The columnist's reasoning most closely conforms to which one of the following principles? A. It is reasonable to take a strong position on an issue if one fully understands the issue and has considered the evidence regarding that issue impartially. B. To ensure that one has impartially considered the evidence regarding an issue on which one has taken a strong opinion, one should avoid misinterpreting or ignoring evidence regarding that issue. C. Anyone who does not understand an issue fully should avoid taking a strong position on it. D. One should try to understand an issue fully if doing so will help one to avoid misinterpreting or ignoring evidence regarding that issue. E. It is reasonable to take a strong position on an issue only if there is important evidence conflicting with that position.

PRINCIPLE EXAMPLE PREMISE: Strong position --> likely misinterpret or ignore impartially. Understand issue --> consider evidence impartially. CONCLUSION -Consider evidence impartially --> -strong position Strong position --> consider evidence impartially In other words... Strong position --> understand issue --> consider evidence impartially ASSUMPTION: Strong position --> understand issue. A. Incorrect. Understand issue and consider evidence impartially --> strong position B. Incorrect. -Misinterpret or -ignore --> consider evidence impartially C. Correct. -Understand issue --> -strong position D. Incorrect -Misinterpret or -ignore --> understand an issue fully E. Incorrect Strong position --> important evidence conflicting

Some credit card companies allow card holders to skip payments for up to six months under certain circumstances, but it is almost never in a cardholder's interest to do so. Finance charges accumulate during the skipped-payment period, and the cost to the cardholder is much greater in the long run. Which one of the following arguments illustrates a principle most similar to the principle underlying the argument above? A. Although incenticides are effective in ridding the environment of insect pests, they often kill beneficial insect species at the same time. Since these beneficial insect species are also important, we must find other ways to combat insect species. C. It is unwise to use highway maintenance funds for construction of new roads. There is some immediate benefit from new roads, but if these funds are not used for maintenance, the total maintenance cost will be greater in the long run.

PRINCIPLE EXAMPLE Some X allow customers to do Y (which is beneficial in the short term), yet doing so is harmful for customers in the long term. A. Incorrect. While there is a discussion of positive and negative consequences, there is no mention of long and short term. Furthermore, there is a type mismatch: the conclusion here is normative. C. Correct.

A park's user fees are employed to maintain the park. When fewer people use the park, it suffers less wear. Thus raising user fees improves park maintenance even if the number of people who stop using the park because of higher fees is great enough to reduce the revenues devoted to maintenance. Which one of the following conforms most closely to the principle illustrated by the statements above? B. A grocery store's overall revenues increase even though it no longer remains open 24 hours daily. The manager theorizes that customers find the store more pleasant because it can be cleaned well during the hours it is closed D. By spending more on zoo maintenance, a city increases the number of zoo patrons. The extra revenue generated by sales more than makes up for the cost of maintenance. E. Library fees have been increased to raise money for book repair. Since the library now has fewer patrons, the books are in better repair even though the number of library patrons has decreased to such an extent that the money available for book repair has decreased.

PRINCIPLE EXAMPLE fewer uses means less wear --> raising fees improves maintenance, even if this leads to fewer users and lower revenues A. Incorrect. Discusses share and profit, not maintenance. B. Incorrect. No discussion of users. Discusses revenues decreasing, not increasing. C. Incorrect. Discusses maintenance deteriorating, not improving D. Incorrect. Discusses users and revenue increasing, not decreasing. E. Correct.

Moralist: A statement is wholly truthful only if it is true and made without intended deception. A statement is a lie if it is intended or its speaker, upon learning that the statement was misinterpreted, refrains from clarifying it. Which one of the following conforms most closely to the principle stated above by the moralist? A. T's statement that he had been abducted by aliens was wholly truthful even though no one has ever been abducted by aliens. After all, T was not trying to deceive. D. Walter's claim that he had done volunteer work was a lie. Even though Walter had worked without pay in his father's factory, he used the phrase "volunteer work" to deceive the interviewer into thinking that that he had worked for a socially beneficial cause. E. The tour guide intended to deceive the tourists when he said that the cabin was centuries old. Still, his statement about the cabin's age was not a lie, for if he thought that his statement was misinterpreted, he would have clarified.

PRINCIPLE EXAMPLE wholly truthful --> true wholly truthful --> not intended to deceive intended to deceive --> lie no clarification of misinterpretation --> lie A. Illegal reversal: not intending to deceive --> wholly truthful; however, not intending to deceive is necessary BUT NOT sufficient. D. Correct. intended to deceive --> lie. E. Incorrect. Since the guide intended to deceive, he lied.

A person's failure to keep a promise is wrong only if, first, doing so harms the one to whom the promise is made and second, all of those who discover the failure to keep the promise lose confidence in the person's ability to keep promises. Which one of the following judgements most closely conforms to the priniciple above? C. G promised to repay R the money he owed her. However, G was unable to keep his promise to R and as a result R suffered a serious financial loss. Thus, G's failure to keep his promise was wrong. D. Because he lost his job, C was unable to repay the money he promised to M. However, M did not need this money nor did she lose confidence in C's ability to keep promises. So, C's failure to keep his promise is not wrong. E. E promised to return the book she borrowed from S, but she could not because she became ill. Not knowing this, S lost confidence in her ability to keep a promise. So, E's failure was wrong.

PRINCIPLE EXAMPLE wrong --> harm + lost confidence This can be separated into: wrong --> harm wrong --> lost confidence Contrapositive: -harm --> -wrong -lost confidence --> -wrong The answer must conform to one or both of these conditional statements. A. Incorrect. The principle relates to breaking promises, not keeping them. B. Incorrect. No harm. C. Incorrect. Illegal Reversal: harm --> wrong D. Correct. Conforms to the contrapositive: -harm and -lost confidence --> -wrong E. Incorrect. Illegal Reversal: lost confidence --> wrong

Cigarette smoking has been shown to be a health hazard; therefore, governments should ban all advertisements that promote smoking. Which of the following principles, if established, most strongly supports the argument? A. Advertisements should not be allowed to show people doing things that endanger their health. E. Advertisements should promote only healthful products.

PRINCIPLE SUPPORT A. Incorrect. There is a difference between advertisements that "promote smoking" and should people doing things that endager their health"; excludes advertisements that promote smoking but do not include images of people smoking. E. Correct. Here, the correct answer plugs the gap beyond what is necessary, and that is okay.

Archaeologist: A large corporation has recently offered to provide funding to restore an archaeological site and to construct facilities to make the site readily accessible to the general public. The restoration will conform to the best current theories about how the site appeared at the height of the ancient civilization it occupied. This offer should be rejected, however, because many parts of the site contain unexamined evidence. Which of the following principles, if valid, justifies the archaeologist's argument A. The ownership of archaeological sites should not be under the control of business interests. B. Any restoration of an archaeological site should represent only the most ancient period of that site's history. C. No one should make judgements about what constitutes the height of the civilization. D. Only those with a true concern for an archaeological site's history should be involved in the restoration of that site. E. The risk of losing evidence relevant to possible future theories should outweigh any advantages of displaying the results of theories already developed.

PRINCIPLE SUPPORT Core P: many parts of the site contain unexamined evidence MC: reject offer A: We should not open up sites for public viewing if the presentation of the site is based on an incomplete examination of the evidence. OR. We should not...if doing so could jeopardize the unexamined evidence. A has nothing to do with evidence. B has nothing to do with unexamined evidence C has nothing to do about whether the site should be open for viewing. D has nothing to do with evidence. E is correct.

Biologist: Researchers believe that dogs are the descendants of domesticated wolves that were bred to be better companions for humans. It has recently been found that some breeds of dogs are much more closely related genetically to wolves than to other breeds of dog. This shows that some dogs are descended from wolves that were domesticated much more recently than others. Which one of the following principles underlie the biologist's argument? A. If one breed of dog is descended from wolves that were domesticated more recently than were the wolves from which most other breeds of dog are descended, the former breed may be more closely related to wolves than other breeds are. B. If one breed of dog is more closely related to wolves than to another breed of dog, then the former breed of dog has more recent undomesticated wolf ancestors than the latter breed has. C. Any breed of dog descended from wolves that were domesticated is more closely related genetically to at least some other breeds of dogs than to wolves. D. If one breed of dog is more closely related to wolves than another breed of dog is, then the former breed of dog is more closely related to wolves than to the latter breed of dog. E. Any two breeds of dogs that are more closely related to each other than to wolves are both descended from wolves that were domesticated long ago.

PRINCIPLE SUPPORT P: Dogs are descended from domesticated wolves. Some dogs are more closely related to wolves than to other dogs. MC: Some dogs are descended from wolves that were domesticated much more recently than others. Conditional statement: Related --> domesticated recently A. Illegal reversal. Domesticated recently --> related B is correct C. False and unsupported by the passage D. Circular logic E. Illegal negation. Related --> -domesticated recently

Arbitrator: the shipping manager admits that he decided to close the old facility on October 14 and to schedule the new facility's opening for October 17. But he also claims that he is not responsible for the business lost. He blames the contractor for not finishing on time, but he, too, is to blame, for he was aware of the contractor's typical delays and should have planned for this contingency. Which of the following principles underlies the arbitrator's argument? A. A manager should take foreseeable problems into account when making decisions. D. A manager should be held responsible for mistakes made by those whom the manager directly supervises. E. A manager, and only a manager, should be held responsible for a project's failure.

PRINCIPLE SUPPORT P: manager was aware of contractor's delays IC: manager should have planned for this contingency MC: manager shares blame w contractor A. Correct. Strengthens gap between premise and IC. D. Detail creep. The stimulus does not state or suggest that the manager directly supervises the contractor. E. Stimulus does not limit the blame to only the contractor. Refer to "he, too, is to blame" in the stimulus.

The Jacksons regularly receive wrong-number calls for Sara, whose phone number was misprinted in a directory. Sara contacted the Jacksons, informing them of the misprint and her correct number. The Jacksons did not lead Sara to believe that they would pass along the correct number, but it would be helpful to Sara and no difficulty for them to do so. Thus, although it would not be wrong for the Jacksons to tell callers trying to reach Sara merely that they have dialed the wrong number, it would be laudable if the Jacksons passed along Sara's correct number. Which one of the following principles, if valid, most helps to justify the reasoning in the argument? A. It is always laudable to do something helpful to someone, but not doing so would be wrong only if one has led that person to believe one would do it. B. Being helpful to someone is laudable when it is not wrong to do so. C. If one can do something that would be helpful to someone else and it would be easy to do, then it is laudable and not wrong to do so. D. Doing something for someone is laudable only if it is difficult for one to do so and it is wrong for one not to do so. E. The only actions that are laudable are those that it would be wrong to refrain from doing, whether or not it is difficult to do so.

PRINCIPLE SUPPORT Premises: Did not mislead. Passing along number is helpful for Sara. Passing along number is not difficult for the Jacksons. Not pass along —> -wrong Pass along —> laudable We can only justifying the judgments -wrong and laudable. The correct principle should connect the concepts of misleading and helping to the judgements of -wrong and laudable. A. Correct. Helpful --> laudable Wrong --> mislead and not help; -mislead and do not help --> -wrong B. Incorrect. Explains why passing along the number is laudable, but does not explain why NOT passing along the number is NOT wrong. C. Incorrect. Explains why passing along the number is laudable, but does not explain why NOT passing along the number is NOT wrong. D. Incorrect. Laudable —> difficult + wrong to not do so. Judgement on the wrong side. E. Incorrect. Laudable —> wrong to not do so. Judgement on the wrong side.

It is a principle of economics that a nation can experience economic growth only when consumer confidence is balanced with a small amount of consumer skepticism. D. Any nation in which the prevailing attitude of consumers is exclusively confidence will not experience economic growth. E. Any nation in which consumer skepticism is balanced with a small amount of consumer confidence will experience economic growth.

PRINCIPLE SUPPORT economic growth --> balance -balance --> -economic growth A. Incorrect. Illegal reversal: balance --> growth B. Incorrect. No reference to balance. C. Incorrect. -Balance --> economic growth D. Correct. Conforms to the contrapositive: -balance --> -economic growth E. Incorrect. Illegal reversal: balance --> economic growth. Detail creep: "small amount of consumer confidence" instead of "small amount of consumer skepticism"

Most people who have taken a seminar for building organization skills in the workplace have indeed become more organized as a result; however, despite having become more organized, few have become more efficient. Which one of the following, if true, would most help to resolve the apparent discrepancy described above? A. Some of the people who are most efficient in the workplace are not among the most organized. B. Most people whose organization skills in the workplace are below average do not take seminars for building organizational skills in the workplace. C. Most seminars for building organizational skills in the workplace are designed for people who have been selected for management training. D. Most people who have taken a seminar for building organizational skills in the workplace have below-average organizational skills before they enroll in the seminar. E. Most people who have taken a seminar for building organizational skills in the workplace consequently expend a great amount of time organizing their activities.

QUANTIFIER Seminar -(most)-> organized (1) Organized -(few)-> efficient (1) What is shared?: Organized Total: 2 No inference can be drawn regarding the seminar and efficiency. A. Incorrect. We do not know anything about individuals not organized. B. Incorrect. We do not know anything about individuals who do not take the seminar. C. Incorrect. Unsupported. Does not resolve the discrepancy. D. Incorrect. No discussion of efficiency, does not resolve the paradox. E. Correct. Suggests a trade-off between efficiency and organization.

In marketing their products, drug companies often send gifts to physicians. According to a recent survey, most physicians believe that their own choices when prescribing drugs are not influenced by drug companies' gifts. The same survey indicates that the majority of physicians believe that most other physicians' prescription choices are influenced by such gifts. What must be true? A. Physicians who do not accept gifts from drug companies are less likely to prescribe unnecessary drugs than those who do accept such gifts. B. Most physicians believe that drug companies should adopt new guidelines that regulate their practices in sending gifts to physicians. C. Some physicians are mistaken either about the degree to which they are influenced by gifts from drug companies or about the degree to which such gifts influence other physicians. D. Some physicians

QUANTIFIER physicians -most-> believe they are not influenced (51) physicians -most-> believe other physicians are influenced (51) What is shared?: physician Total: 102 A. Incorrect. Out of scope. We are not given any information about physicians who do not accept gifts. B. Incorrect. Discussion of regulations is out of scope. C. Some physicians believe they are not influenced by gifts but that other physicians are.

Banking analyst: banks often offer various services to new customers at no charge. But this is not an ideal business practice, since regular, long-term customers, who make up the bulk of the business for most banks, are excluded from these special offers. Which of the following, if true, most strengthens the banking analyst's argument? A. Most banks have similar charges for most services and pay similar interest rates on deposits. B. Banks do best when offering special privileges only to their most loyal customers. C. Offering services at no charge to all of its customers would be prohibitively expensive for the bank. D. Once they have chosen a bank, people tend to remain loyal to that bank. E. Some banks that offer services at no charge to new customers are very successful.

STRENGTHEN A: Offering services to long-term customers would be beneficial for the bank. A. Incorrect. Does not strengthen. B. C. Incorrect. Weakens. D. Incorrect. Weakens. Suggests that offering special services to specific members does not matter. E. Incorrect. Weakens.

Birds and mammals can be infected with West Nile virus only through mosquito bites. Mosquitos, in turn, become infected with the virus when they bite certain infected birds or mammals. The virus was originally detected in northern Africa and spread to North America in the 1990s. Humans sometimes catch West Nile virus, but the virus never becomes abundant enough in human blood to infect a mosquito. The statements above, if true, most strongly support which of the following?: A. West Nile virus will never be a common disease among humans. B. West Nile virus is most common in those parts of North America with the highest density of mosquitos. C. Some people who become infected with West Nile virus never show symptoms of illness. D. West Nile virus infects more people in northern Africa than it does in North America. E. West Nile virus was not carried to North America via an infected person.

STRENGTHEN Mosquito bites infect humans and birds. Mosquitos become infected when they bite certain infected birds or mammals. Mosquitos cannot become infected when they bite humans. A. Issue of degree. C. Out of scope D. Out of scope E. Correct. Since humans cannot infect mosquitos and only mosquitos can infect others, an infected person was not the cause of the virus spreading to North America.

People who have political power tend to see new technologies as a means of extending or protecting their power, whereas they generally see new ethical arguments and ideas as a threat to it. Therefore, technical ingenuity usually brings benefits to those who have this ingenuity, whereas ethical inventiveness brings only pain to those who have this inventiveness. Which one of the following statements, if true, most strengthens the argument? A. Those who offer new ways of justifying current political power often reap the benefits of their own inventions. B. Politically powerful people tend to reward those who they believe are useful to them and to punish those who they believe are a threat. C. Ethical inventiveness and technical ingenuity are never possessed by the same individual. D. New technologies are often used by people who strive to defeat those who currently have political power. E. Many people who possess ethical inventiveness conceal their novel ethical arguments for fear of retribution by the politically powerful.

STRENGTHEN P: politically powerful see tech as good and new ethics as threatening. C: new tech brings benefits to those who invent it and new ethics brings pain to those who invent them. A is incorrect. There is a difference between "extending and protecting political power" mentioned in the stimulus and "justifying political power" mentioned in A. B is correct. It connects the ideas of political powers described in the premise to the action of political powers described in the conclusion. C is incorrect. Someone with both traits may receive benefits from one or pain from another. Not necessary.

Principle: when none of the fully qualified candidates for a new position at Arvue Corporation currently works for the company, it should hire the candidate who would be most productive in that position. Application: Arvue should not hire Krall for the new position, because Delacruz is a candidate and is fully qualified. Which one of the following, if true, justifies the above application of the principle? A. All of the candidates are fully qualified for the new position, but none already work for Arvue. B. Of all the candidates who do not already work for Arvue, Delacruz would be the most productive in the new position. C. Krall works for Arvue, but Delacruz is the candidate who would be most productive in the new position. D. Several candidates currently work for Arvue, but Krall and Delacruz do not. E. None of the candidates already works for Arvue, and Delacruz is the candidate who will be most productive in the new position.

STRENGTHEN Principle: -qualified candidates for new position work at company —> company should hire most productive candidate D must be...qualified, not currently working for Arvue, and more productive than K A. Incorrect. Does not establish D as more productive than K. B. Incorrect. K could be a qualified candidate for the new position who currently works for the company (thus justifying that K should be hired) C. Incorrect. K could be a qualified candidate (thus justifying that K should be hired). D. Incorrect. Does not establish D as more productive than K. E. Correct

In most industrial waste products that contain the toxic chemical XTX, the concentration of this chemical is approximately 1000 parts per million. A federal law intended to reduce the harm that can result from the introduction of XTX into the environment permits a company to dispose of these waste products in a dump for hazardous waste, but only if the concentration of XTX is below 500 parts per million. Waste products with concentrations above that level must be destroyed by incineration. The law further specifies that manufacturers may not dilute XTX-containing waste products to bring their concentration of XTX down to a permissible level for dumping. Which one of the following, if true, argues most strongly for the inclusion of the anti dilution provision of the law? A. If improperly incinerated, waste products containing undiluted concentrations of XTX can release into the environment a gaseous form of the chemical that is more than twice as toxic as XTX in its liquid state. B. If present in the environment in sufficient quantities, the diluted XTX is as harmful as the more concentrated XTX. Diluted XTX still harms the environment. C. When XTX is exposed to sunlight and oxygen, it eventually breaks down into a number of components that individually and collectively carry no risk of environmental harm. D. Most owners of dumps for hazardous waste are willing to accept XTX for disposal in their facilities only in concentrations below 800 parts per million. E. To manufacturers, the cost of diluting and disposing of waste products containing XTX is approximately the same as the cost of destroying these products by incineration.

STRENGTHEN Unusual strengthen question whose position being strengthened is not actually a conclusion of the stimulus, but rather implied from the question itself. PREMISE: 1. law attempts to reduce harm from waste in environment 2. dump under 500 parts, incinerate above 500 parts 3. manufacterurs may not dilute CONCLUSION (implied from the question stem): The law should include an anti-dilution provision. A. Errors in incineration do not apply to anti-dilution. B. Correct! C. Does not apply to dilution. D. Does not apply to dilution for the purposes of DUMPING. E. Weakens. Implies that there is no financial incentive for diluting.

Physician: the rise in blood pressure that commonly accompanies aging often results from a calcium deficiency. The deficiency is frequently caused by a deficiency in the active form of vitamin D, needed in order for the body to absorb calcium. Since calcium in one glass of milk per day can easily make up for any underlying calcium deficiency, some older people can lower their blood pressure by drinking milk. The physician's conclusion is properly drawn if which of the following is assumed? A. There is in milk, in a form that older people can generally utilize, enough of the active form of vitamin D and any other substances needed in order for the body to absorb the calcium in that milk. B. Milk does not contain any substance that is likely to increase BP in older people. C. Older people's drinking one glass of milk per day does not contribute to a deficiency in the active form of vitamin D needed in order for the body to absorb the calcium in that milk. D. People who consume high quantities of calcium together with the active form of vitamin D and other substances needed in order for the body to absorb calcium have normal blood pressure. E. Anyone who has a deficiency in the active form of vitamin D also has a calcium deficiency.

SUFFICIENT ASSUMPTION Make sure to match the argument in strength. The stimulus uses language such as "often" and "some." P1: decrease in Vitamin D → decrease in C → increase in BP P2: Milk → increase in C C: Milk → decrease in BP Assumption: Milk → increase in Vitamin D → increase in C → decrease in BP *These are are not conditionals but rather correlated relationships A. Fills the gap between milk and vitamin D. Milk —> increase in vitamin D —> increase in C D. Decrease in vitamin D —> decrease in C. This was already stated in the premise. It also uses extreme language that does not correspond with the stimulus. Incorrect.

If the budget does not allow for more dairy inspectors to be hired, most of the large dairies in the Central Valley will not meet federal standards governing the disposal of natural wastes, which can seep into streams and groundwater. The new district budget, however, does not allow for the hiring of more dairy inspectors. Consequentially, most of the district's drinking water is likely to become polluted. The conclusion above follows logically if which one of the following is assumed? A. If most of the dairies in the Central Valley meet federal standards for the disposal of natural wastes, it is unlikely that most of the district's drinking water becomes polluted. B. To keep all the drinking water in the district clean requires more dairy inspectors to monitor the dairies' disposal of natural wastes. C. All of the district's drinking water is likely to become polluted only if all of the large dairies isn't be Central Valley do not meet federal standards for the disposal of natural waste products. D. Most of the district's drinking water is likely to become polluted if most of the large dairies in the Central Valley do not meet federal standards.

SUFFICIENT ASSUMPTION P1: -more dairy inspectors -(most)-> dairies do not meet standards. P2: -more dairy inspectors C: pollution Assumption: -more dairy inspectors —> pollution A. Incorrect. Illegal negation: dairies meet standards —> -pollution B. Correct. -pollution —> more dairy inspectors. C. Incorrect. Illegal reversal: pollution —> dairies do not meet standards. D. Incorrect. Dairies do not meet standards —> pollution, yet we need to link -more dairy inspectors —> pollution.

Principle: A police officer is eligible for a Mayor's Commendation if the officer has an exemplary record, but not otherwise; an officer eligible for the award who did something this year that exceeded what could be reasonable expected of a police officer should received the award if the act saved someone's life Conclusion: Officer Franklin should receive a Mayor's Commendation but Officer Penn should not From which of the following sets of facts can the conclusion be properly drawn using the principle? A. In saving a child from drowning this year, F and P both risked their lives beyond what could be reasonably expected of a police officer. F has an exemplary record but P does not. B. Both F and P have exemplary records, and each officer saved a child from drowning earlier this year. However, in doing so, F went beyond what could be reasonably expected; P did not ...

SUFFICIENT ASSUMPTION P: Exemplary record --> eligible -Exemplary record --> -eligible C: Eligible + exceed + save life --> award A. Correct. Satisfies all conditions. B. Incorrect. Eligibility is both sufficient and necessary. In A, P lacks eligibility, so he will NOT receive the award. Furthermore, in B, P did not go beyond expectations when saving the child's life, but he may have gone beyond expectations during other acts. Thus, a lack of exceeding expectations is not sufficient to guarantee that P does NOT receive the award.

Many artists claim that art critics find it is easier to write about art that they dislike than art they like. Whether or not this hypothesis is correct, most art criticism is devoted to art works that fail to satisfy the critic. Hence it follows that most art criticism is devoted to works other than the greatest work of art. The conclusion above is properly drawn if which one of the following is assumed? A. No art critic enjoys writing about art works that he or she dislikes intensely. B. All art critics find it difficult to discover art works that truly satisfy them. C. A work of art that receives extensive critical attention can thereby become more widely known than it otherwise would have been. D. The greatest works of art are never recognized as such until long after the time of their creation. E. The greatest works of art are works that inevitably satisfy all critics.

SUFFICIENT ASSUMPTION P: Most art criticism is about art that fails to satisfy the critic. C: Most art criticism is about art other than the greatest works of art. A: If a work of art does not satisfy the critic, it is not the greatest. A. False. Contradicts premise. Fails to mention greatest art and relate to the conclusion. B. False. Discovery is unrelated to argument and not inferable. Fails to mention greatest art and relate to the conclusion. C. False. Answer addresses publicity rather than the type of art. Fails to mention greatest art and relate to the conclusion. D. False. The stimulus does not address the length of time between discovery and criticism. Fails to mention criticism and relate to the premise. E. Correct. Contrapositive of predicted assumption. -Great --> -satisfy.

Although Pluto has an atmosphere and is much larger than any asteroid, Pluto is not a true planet. Pluto formed in orbit around the planet Neptune and was then ejected from orbit around Neptune when Triton, Neptune's largest moon, was captured by Neptune's gravity. The conclusion of the argument follows logically if which one of the following is assumed? A. No celestial body can simultaneously be a moon and a planet. B. Not all celestial bodies have an atmosphere and orbit the sun are true planets. C. If Pluto had not been ejected from its orbit around Neptune, Pluto would not have its current around the sun and would still be a moon. D. The size of a celestial body in orbit around the sun is not relevant to determining whether or not it is a true planet. E. For a celestial body to be a true planet, it must have formed in orbit around the sun exclusively.

SUFFICIENT ASSUMPTION P: Pluto formed around Neptune's orbit, then ejected. C: Not a planet. A. Incorrect. Not enough evidence to state that Pluto is a moon. B. Incorrect. Unsupported. C. Incorrect. Unsupported, and even if it was, it would not connect the premise to conclusion (not a PLANET) D. Incorrect. Size is not discussed. E. If NOT exclusively orbit around sun --> not a planet.

Oil company representative: We spent more money on cleaning the otters affected by our recent oil spill than has been spent on any previous marine mammal rescue project. This shows our concern for the environment. Environmentalist: You have no such concern. Your real concern is evident in your admission to the press that news photographs of oil-covered otters would be particularly damaging to your public image, which plays an important role in your level of sales. The environmentalist's conclusion would be properly drawn if it were true that the: A. Oil company cannot have more than one motive for cleaning the otters affected by the oil spill. B. Otter population in the area of the oil spill could not have survived without the cleaning project. C. Oil company has always shown a high regard for its profits in choosing its courses of action. D. Government would have spent the money to clean the otters if the oil company had not agreed to do it. E. Oil company's efforts toward cleaning the affected otters have been more successful than have such efforts in previous projects to clean up oil spills.

SUFFICIENT ASSUMPTION P: The oil company is concerned about bad publicity from oil-covered otters. C: The oil company does not have concern for the environment. A. True. If the company can only have one motive, and the motive of protecting public image is true, then the motive to protect the environment is false. B. False. Does not relate to motive. C. False. Premise booster. Tempting because it suggests that the company may have a motive besides environmental concern. However, the stimulus already states that the company is motivated by something other than environmental concern. This answer does not address the question of whether the company can hold multiple motives. D. False. Does not relate to motive. E. False. Does not relate to motive.

Unemployment will soon decrease. If total government spending significantly increases next year, the economy will be stimulated in the short term and unemployment will decrease. If, on the other hand, total government spending significantly decreases next year, businesses will retain more of their earnings in the short term and employ more workers, thereby decreasing unemployment. The conclusion drawn is properly inferred if which of the following is assumed? A. Either total government spending will significantly decrease next year or else total government spending will significantly increase next year. E. If the economy is not stimulated and businesses do not retain more of their earnings, then unemployment will not decrease.

SUFFICIENT ASSUMPTION P: sig increase --> econ stim in short term + unemployment decreases P: sig decrease --> business retain --> unemployment decreases C: unemployment decreases A. Correct. E. Incorrect negation of the premises. -econ stim and -businesses retain —> -unemployment decreases

Some governmental economists view their home countries as immune to outside influence. But economies are always open systems; international trade significantly affects prices and wages. Just as physicists learned the shortcomings of a mechanics based on idealizations such as the postulation of perfectly frictionless bodies, government economists must look beyond national borders if their nations' economies are to prosper. The argument's conclusions follows logically if which one of the following is assumed? A. A national economy cannot prosper unless every significant influence on it has been examined by that nation's government economists. B. Economics is weakly analogous to the physical sciences. C. Economic theories relying on idealization are generally less accurate than economic theories that do not rely on idealizations. D. International trade is the primary significant variable influencing prices and wages. E. Some governmental economists have been ignoring the effects of international trade on prices and wages.

SUFFICIENT ASSUMPTION Stimulus uses an analogy to support its point. P: Economies are open systems, affected by international influences. C: Government economists need to look beyond their national borders for their economist to proposer. A (must link economies to actions of economists): Economists must look influences on economies in order for those economies to prosper. A. Correct. Assumption: economy prospers --> economists examine, which matches the conclusion: economy prospers --> economists examine international influences. B. Incorrect. Does not mention actions of economists. "Weakly" does not provide a strong enough or sufficient. C. Incorrect. Out of scope; stimulus does not offer a connection between economic theory and idealization D. Incorrect. Premise repeater. E. Incorrect. Does not establish what economists should or must do.

Letter to the editor: When your newspaper reported the (admittedly extraordinary) claim by Mr. Hanlon that he saw an alien spaceship, the tone of your article was very skeptical despite the fact that Hanlon has over the years proved to be a trusted member of the community. If Hanlon claimed to have observed a rare natural phenomenon like a large meteor, your article would not have been skeptical. So your newspaper exhibits an unjustified bias. The argument in the letter conflicts with which one of the following principles? A. If a claim is extraordinary, it should not be presented uncritically unless it is backed by evidence of an extraordinarily high standard. B. One should be skeptical of claims that are based upon testimonial evidence that is acquired only through an intermediary source. C. If a media outlet has trusted a source in the past and the source has a good reputation, the outlet should continue to trust the source. D. People who think they observe supernatural phenomena should not publicize that fact unless they can present corroborating evidence. E. A newspaper should not publish a report unless it is confirmed by an independent source.

WEAKEN Careful; make sure to weaken the position of the columnist and not the newspaper! In other words, you want to weaken the criticism that the newspaper is biased by justifying that it should be skeptical about extraordinary sightings. A. Correct. B. Incorrect. Justifies skepticism in certain cases, but we do not know if Hanlon's claims were delivered via an intermediate source. C. Incorrect. Does not justify skepticism for extraordinary but not rare sightings. D. Incorrect. Addresses the Hanlon's but not the news paper's behavior. E. Incorrect. The principle should justify skepticism, not publication.

Mayor: local anti tobacco activities activists are calling for expanded anti smoking education programs paid for by revenue from heavily increased taxes on cigarettes sold in the city. Although the effectiveness of such educational programs is debatable, there is strong evidence that the taxes themselves would produce the sought after reduction in smoking. Surveys show that cigarette sales drop substantially in cities that impose stiff tax increases on cigarettes. Which one of the following, if true, most undermines the reasoning above? A. A city-imposed tax on cigarettes will substantially reduce the amount of smoking in the city if the tax is burdensome to the average consumer. B. Consumers are more likely to continue buying a product if its price increases due to higher taxes that if its price increases for some other reason. C. Usually, cigarette sales will increase substantially in areas surrounding the city. D. People who are well informed about the effectives of long term tobacco use are significantly less likely to smoke than people who are not informed. E. Anti smoking education programs that are funded by taxes on cigarettes will tend to lose their funding if they are successful.

WEAKEN MC: regardless of education programs, taxes on tobacco products will decrease the sale of tobacco products. A. Incorrect. We can not determine from the stimulus if the tax is burdensome or not. B. Incorrect. Even if consumers are more likely to purchase taxes than non taxes products, they may still decrease overall purchase of those products. C. Correct. D. Incorrect. The MC defends the efficacy of taxes alone, not educational programs. E. Same reasoning as D.

Detective: because the embezzler must have had specialized knowledge and access to internal financial records, we can presume that the embezzler worked for XYZ Corporation as either an accountant or an actuary. But an accountant would probably not make the mistakes in ledger entries that led to the discovery of the embezzlement. Thus it is likely that the embezzler is one of the actuaries. Each of the following WEAKENS the argument EXCEPT: A. The actuaries' activities while working for the XYZ Corporation were more closely scrutinized by supervisors than were the activities of accountants. B. There is evidence of breaches in computer security at the time of embezzlement that could have given persons outside XYZ Corporation access to internal financial records. C. XYZ Corporation employs eight accountants, whereas it has only two actuaries on its staff. D. An independent report released before the crime took place concluded that XYZ Corporation was vulnerable to embezzlement. E. Certain security measures at XYZ Corporation made it more difficult for the actuaries to have access to internal financial records than for the accountants.

WEAKEN P: Embezzler must access records—either accountant or actuary. Accountant would probably not make the mistakes made. C: Embezzler is likely an actuary. A. False. Suggests that if there were more closely scrutinized, actuaries are less likely to make embezzle. B. False. Weakens argument that the actuaries are likely the embezzlers. C. False. Weakens argument that actuaries are likely the embezzlers, because it is statistically less likely. D. Correct. Strengthens premise that embezzlement occurred, yet unclear bearing on C. E. False. Weakens argument that actuaries are likely the embezzlers.

Loggerhead turtles live and breed in distinct groups, of which some are in the Pacific Ocean and some are in the Atlantic. New evidence suggests that juvenile Pacific loggerheads that feed near the Baja peninsula hatch in Japanese waters 10,000 kilo away. 95% of the DNA samples taken from the Baja turtles match those taken from the turtles at the Japanese nesting sites. Which one of the following, if true, most seriously weakens the reasoning above? A. Nesting sites of loggerhead turtles have been found off the Pacific coast of North America several thousand kilometers north of the Baja peninsula. B. The distance between nesting sites and feeding sites of Atlantic loggerhead turtles is less than 5,000 kilometers. C. Loggerhead hatchlings in Japanese waters have been declining in number for the last decade while the number of nesting sites near the Baja peninsula has remained constant. D. 95% of the DNA samples taken from the Baja turtles match those taken from the Atlantic loggerhead turtles.

WEAKEN Premise: 95% DNA match Conclusion: Pacific loggerhead turtles that feed near the Baja peninsula hatch in Japanese waters 10,000 km away Assumption: 95% DNA match is sufficient to prove the connection that these are the same turtles, A is not correct. It is tempting because it posits that the turtles nesting in Japan may come from the Pacific coast of North America instead of Baja. However, ultimately, the presence of these other sites does not weaken the logic that the Baja turtles then hatch in Japanese waters. There is no proof that these sites are more likely places. This answer does not address the assumption about DNA. B is not correct. We cannot determine whether 5000 km is a norm or a maximum. C is not correct. Nesting sites and feeding sites in Baja are different. It is possible that feeding sites have been unchanged, thus allowing turtles to hatch in Japan, even if nesting sites have changed. D is correct. This answer does not suggest that the turtles hatched in Japan came from the Atlantic. The premise states that the Atlantic and Pacific turtles are distinct, and we treat this as fact. Instead, D suggests that the assumption of 95% DNA match is not strong enough to justify the conclusion.

Geologist: the dominant view that petroleum formed from the fossilized remains of plants and animals deep in earth's crust has been challenged by scientists who hold that it formed, not from living material, but from deep carbon deposits dating from the formation of earth. But their theory is refuted by the presence in petroleum of biomarkers, molecules indicating the past or present existence of a living organism. Which one of the following, if true, most weakens the geologist's argument? A. Fossils have been discovered that are devoid of biomarkers. B. Living organisms only emerged long after the earth's formation. C. It would take many millions of years for organisms to become petroleum. D. Certain strains of bacteria thrive deep inside the earth's crust. E. Some carbon deposits were formed from the fossilized remains of plants.

WEAKEN Stimulus Breakdown: Current view: Oil (petroleum) formed from dead plants/animals. New view: Oil formed from carbon deposits. Author premise: Biomarkers are indicators of living organisms. Oil has biomarkers. Author conclusion: Biomarkers in oil disproves the new view. A. No bearing. We're not worried about the biomarkers in fossils; we're worried about biomarkers in petroleum. Furthermore, we need to weaken the author's refutation of the new view, but that does not mean that we must strengthen the old view. Finally, this answer choice only states that SOME fossils do not contain biomarkers; we would need to assume that ALL fossils contain no biomarkers or NO fossils contain biomarkers in order to weaken the credibility of biomarkers as evidence. B. No bearing. The argument doesn't say that petroleum formed from fossils of living organisms dating from the Earth's formation. The carbon deposit argument mentions this, not the fossil argument. C. No bearing. Again, the geologist doesn't mention a time frame. We have no indication of when petroleum supposedly developed. D. Sort of weakens. If the petroleum that formed in the crust was surrounded by bacteria, maybe it's those bacteria that caused the biomarkers to form in petroleum. Keep it. E. Strengthen. If fossils formed carbon deposits and carbon deposits formed petroleum, then fossils did indirectly hep to form petroleum, making the geologist, although misleading, still correct.

Recently discovered prehistoric rock paintings on small islands off the northern coast of Norway have archaeologists puzzled. The predominant theory about northern cave paintings was that they were largely a description of the current diets of the painters. This theory cannot be right, because the painters must have needed to eat the sea animals populating the waters north of Norway if they were to make the long journey to and from the islands, and there are no paintings that unambiguously depict such creatures. Each of the following, if true, weakens the argument against the predominant about northern cave paintings EXCEPT: A. Once on these islands, the cave painters hunted and ate land animals. B. Parts of the cave paintings on the island did not survive the centuries. C. The cave paintings that were discovered on the island depicted many land animals. D. Those who did the cave paintings that were discovered on the island had unusually advanced techniques of preserving meats. E. The cave paintings on the islands were done by the original inhabitants of the island who ate the meat of land animals.

WEAKEN: EXCEPT P: painters must have eaten sea animals north of Norway; no paintings unambiguously depict such creatures C: theory that paintings describe diets is false A weakens. The painters did paint their diets; these diets did not include sea animals B weakens. The evidence presented by the author may be limited. C is not directly related. This is correct D weakens. It weakens the premise that painters ate fish. It suggests that painters ate meats instead. E weakens. The painters did paint their diets; these diets did not include sea animals