Logical Reasoning
After replacing his old gas water heater with a new, pilotless, gas water heater that is rated as highly efficient, Jimmy's gas bills increased. Each of the following, if true, contributes to an explanation of the increase mentioned above EXCEPT: (A) The new water heater uses a smaller percentage of the gas used by Jimmy's household than did the old one. (B) Shortly after the new water heater was installed, Jimmy's uncle came to live with him, doubling the size of the household. (C) After having done his laundry at a laundromat, Jimmy bought and started using a gas dryer when he replaced his water heater. (D) Jimmy's utility company raised the rates for gas consumption following installation of the new water heater. (E) Unusually cold weather following installation of the new water heater resulted in heavy gas usage.
Evaluate potential explanations for the discrepancy that exists in the stimulus A
Several thousand years ago, people in what is now North America began to grow corn, which grows faster and produces more food per unit of land than do the grains these people had grown previously. Corn is less nutritious than those other grains, however, and soon after these people established corn as their staple grain crop, they began having nutrition-related health problems. Yet the people continued to grow corn as their staple grain, although they could have returned to growing the more nutritious grains. Which one of the following, if true, most helps to explain why the people mentioned continued to grow corn as their staple grain crop? A. The variety of corn that the people relied on as their staple grain produced more food than did the ancestors of that variety. B. Modern varieties of corn are more nutritious than were the varieties grown by people in North America several thousand years ago. C. The people did not domesticate large animals for meat or milk, either of which could supply nutrients not provided by corn. D. Some of the grain crops that could have been planted instead of corn required less fertile soil in order to flourish than corn required. E. The people discovered some years after adopting corn as their staple grain that a diet that supplemented corn with certain readily available non grain foods significantly improved their health.
Explain the discrepancy E
The postmodern view involves the rejection of modern assumptions about order and the universality of truth. The grand theories of modern era are now seen as limited by the social and historical contexts in which they were elaborated. Also, the belief in order has given way to a belief in the importance of irregularity and chaos. It follows that we inhabit a world full of irregular events, and in which there are no universal truths. The argument's reasoning is questionable because the argument A) infers that something is the case because it is believed to be the case B) uses the term "universal" ambiguously C) relies on the use of emotional terms to bolster its conclusion D) uses the term "order" ambiguously E) fails to cite examples of modern theories that purport to embody universal truths
Flaw in the reasoning A
Studies show that the most creative engineers get their best and most useful ideas only after doodling and jotting down what turn out to be outlandish ideas. Now that many engineers do their work with computers instead of on paper, however, doodling is becoming much less common, and some experts fear that the result will be fewer creative and useful engineering ideas. These experts argue that this undesirable consequence would be avoided if computer programs for engineering work included simulated notepads that would allow engineers to suspend their "serious" work on the computer, type up outlandish ideas, and then quickly return to their original work. Which one of the following is an assumption on which the experts' reasoning depends? (A) Most creative engineers who work with paper and pencil spend about as much time doodling as they spend on what they consider serious work. (B) Simulated notepads would not be used by engineers for any purpose other than typing up outlandish ideas. (C) No engineers who work with computers keep paper and pencil near their computers in order to doodle and jot down ideas. (D) The physical act of working on paper is not essential in providing engineers with the benefits that can be gained by doodling. (E) Most of the outlandish ideas engineers jot down while doodling are later incorporated into projects that have practical applications.
Flaw: 1+1 does not equal 3 E
The caterpillar of the monarch butterfly feeds on milkweed plants, whose toxins make the adult monarch poisonous to many predators. The viceroy butterfly, whose caterpillars do not feed on milkweed plants, is very similar in appearance to the monarch. Therefore, it can be considered that the viceroy is so seldom preyed on because of its visual resemblance to the monarch. Which of the following, if it were discovered to be true, would most seriously undermine the argument? (A) Some predators do not have a toxic reaction to insects that feed on milkweed plants. (B) Being toxic to predators will not protect individual butterflies unless most members of the species to which such butterflies belong are similarly toxic. (C) Some of the predators of the monarch butterfly also prey on viceroys. (D) The viceroy butterfly is toxic to most predators. (E) Toxic to predators is the principal means of protection for only a few butterfly species.
Flaw: 1+1 does not equal 3 (weakens) D
Newspaper editor: Law enforcement experts, as well as most citizens, have finally come to recognize that legal prohibitions against gambling all share a common flaw: no matter how diligent the effort, the laws are impossible to enforce. Ethical qualms notwithstanding, when a law fails to be effective, it should not be a law. That is why there should be no legal prohibition against gambling. Which one of the following, if assumed, allows the argument's conclusion to be properly drawn? (A) No effective law is unenforceable (B) All enforceable laws are effective (C) No legal prohibitions against gambling are enforceable (D) Most citizens must agree with a law for the law to be effective (E) Most citizens must agree with a law for the law to be enforceable
Flaw: Apples not equal to Oranges A
Advertisement: Anyone who thinks moisturizers are not important for beautiful skin should consider what happens to the earth, the skin of the word, in times of drought. Without regular infusions of moisture the ground becomes lined and cracked and its lush loveliness fades away. Thus your skin, too, should be protected from the protection provided by regular infusions of Dewyfresh the drought-defying moisturizer. The Dewyfresh advertisement exhibits which one of the following errors of reasoning? (A) It treats something that is necessary for bringing about a state of affairs as something that is sufficient to bring about that state of affairs. (B) It treats the fact that two things regularly occur together as proof that there is a single thing that is the cause of them both. (C) It overlooks the fact that changing what people think is the case does not necessarily change what is the case. (D) It relies on the ambiguity of the term "infusion." which can designate either a process or the product of that process. (E) It relies on an analogy between two things that are insufficiently alike in the respects in which they would have to be alike for the conclusion to be
Flaw: Apples not equal to Oranges E
Psychologist: Some astrologers claim that our horoscopes completely determine our personalities, but this claim is false, I concede that identical twins---who are, of course, born at practically the same time---often do have similar personalities. However, birth records were examined to find two individuals who were born 40 years ago on the same day and at exactly the same time---one in a hospital in Toronto and one in a hospital in New York. Personalities of these two individuals are in fact different. Which one of the following is an assumption on which the psychologist's argument depends? (A) Astrologers have not subjected their claims to rigorous experimentation. (B) The personality differences between the two individuals cannot be explained by the cultural difference between Toronto and New York. (C) The geographical difference between Toronto and New York did not result in the two individuals having different horoscopes. (D) Complete birth records for the past 40 years were kept at both hospitals. (E) Identical twins have identical genetic structures and usually have similar home environments
Flaw: Find what is wrong with argument and then find an answer that needs to be true for the argument to work C
Altogether, the students in Ms. Tarnowski's Milton Elementary School class collected more aluminum cans than did the students in any of the school's other classes. Therefore, the Milton student who collected the most aluminum cans was in Ms. Tarnowski's class. Which one of the following arguments contains flawed reasoning that is most parallel to that in the argument above? (A) Altogether, more trees were planted by the students in Mr. Kelly's class than were planted by those in Mr. Liang's class and Mr. Jackson's class combined. Therefore, Mr. Kelly's students planted more trees than Mr. Jackson's students planted. (B) More than half of Milton Elementary School's students play in the band and more than half of the school's students sing in the choir. Therefore, every student at Milton Elementary School either plays in the band or sings in the choir. (C) Mr. Rowe's Milton Elementary School class raised more money by selling candy bars than Ms Hunt's class raised by holding a raffle. Therefore, the number of candy bars sold by Mr. Rowe's class was greater than the number of raffle tickets sold by Ms. Hunt's class. (D) The total number of tickets to the school fair sold by the students in Ms. Ramirez's Milton Elementary School class was greater than the number sold by Milton students from any other class. Therefore, the Milton student who sold the most tickets to the school fair was a student in Ms. Ramirez's class. (E) Ms. Ventura's Milton Elementary School class assembled more birdhouses than did any of the school's other classes. Since Ms Ventura's class had fewer students than any other Milton class, her students assembled more birdhouse on average than did the students in any other Milton class.
Flaw: Piece not equal to the puzzle D
Bacteria from food can survive for several days on the surface of plastic cutting boards, but bacteria can penetrate wooden cutting boards almost immediate in leaving the surface free of contamination. Therefore, wooden cutting boards, unlike plastic cutting boards, need not be washed in order to prevent their contaminating food that is cut on them; wiping them off to remove food debris is sufficient. Which one of the following is an assumption on which the argument depends? (A) Washing plastic cutting boards does not remove all bacteria from the surface. (B) Prevention of bacteria contamination is the only respect in which wooden cutting boards are superior to plastic cutting boards. (C) Food that is not already contaminated with bacteria can be contaminated only by being cut on contaminated cutting boards. (D) Bacteria that penetrate into wooden cutting boards do not reemerge on the surface after the cutting boards have been used. (E) Washing wooden cutting boards kills bacteria below the surface of the cutting boards.
Flaw: Piece not equal to the puzzle D
Newspaper editor: Law enforcement experts, as well as most citizens, have finally been come to recognize that legal prohibitions against gambling all share a common flaw: no matter how diligent the effort, the laws are impossible to enforce. Ethical qualms notwithstanding, when a law fails to be effective, it should be a law. That is why there should be no legal prohibition against gambling. Which of the following, if assumed, allows the argument's conclusion to be properly drawn? (A) No effective law is unenforceable. (B) All enforceable laws are effective. (C) No legal prohibitions against gambling are enforceable. (D) Most citizens must agree with a law for the law to be effective. (E) Most citizens must agree with a law for the law to be enforceable.
Flaw: Piece not equal to the puzzle (sufficient assumption) A
Hospital executive: At a recent conference on nonprofit management, several computer experts maintained that the most significant threat faced by large institutions such as universities and hospitals is unauthorized access to confidential data. In light of this testimony, we should make the protection of our clients' confidentiality our highest priority. The hospital executive's argument is most vulnerable to which one of the following objections? (A) The argument confuses the causes of a problem with the appropriate solutions to that problem. (B) The argument relies on the testimony of experts whose expertise is not shown to be sufficiently broad to support their general claim.(C) The argument assumes that a correlation between two phenomena is evidence that one is the cause of the other. (D) The argument draws a general conclusion about a group based on data about an unrepresentative sample of that group. (E) The argument infers that a property belonging to large institutions belongs to all institutions.
Flaw: What is wrong with the argument? B
Driver: My friends say I will one day have an accident because I drive my sports car recklessly. But I have done some research, and apparently minivans and larger sedans have very low accident rates compared to sports cars. So trading my sports car in for a minivan would lower my risk of having an accident. The reasoning in the driver's argument is most vulnerable to criticism on the grounds that this argument (A) infers a cause from a mere correlation (B) relies on a sample that is too narrow (C) misinterprets evidence that a result is likely as evidence that the result is certain (D) mistakes a condition sufficient for bringing about a result for a condition necessary for doing so (E) relies on a source that is probably not well-informed
Flaw: What's wrong with the argument? A
A group of citizens opposes developing a nearby abandoned railroad grade into a hiking trail. Its members argue that trail users will likely litter the area with food wrappers and other debris. But this objection is groundless. Most trail users will be dedicated hikers who have great concern for the environment. Consequently, development of the trail should proceed. The argument above is flawed in that it (A) bases its conclusion mainly on a claim that an opposing argument is weak (B) Illicitly infers that because each member of a set has a certain property that set itself has the property (C) Illicitly assumes as one of its premises the contention it purports to show (D) Illicitly infers that an attribute of a few users of the proposed trail will characterize a majority of users of the trail (E) attacks the citizens in the group rather than their objection to developing the trail
Flawed Reasoning A
There are already more great artworks in the world than any human being could appreciate in a lifetime, works capable of satisfying virtually any taste imaginable. Thus, contemporary artists, all of whom believe that their works enable many people to feel more aesthetically fulfilled than they otherwise could, are mistaken. The argument is most vulnerable to criticism on the grounds that it (A) overlooks that possibility that not all contemporary artists believe that their works enable many people to feel more aesthetically fulfilled than they otherwise could (B) presumes, without providing justification, that most human beings are inclined to take the time to appreciate many greats artworks (C) presumes, without providing justification, that the value of an artwork depends on the degree to which human beings appreciate it (D) overlooks the possibility that the work of at least one contemporary artist is appreciated by many people whose access to the great majority of other artworks is severely restricted (E) presumes, without providing justification, that the number and variety of great artworks already in the world affects the amount of aesthetic fulfillment derivable from any contemporary artwork
Flawed Reasoning D
Agricultural scientist: Wild apples are considerably smaller than cultivated apples found in supermarkets. In one particular region, archaeologists have looked for remains of cultivated apples dating from 5,000 years ago, around the time people first started cultivating fruit. But the only remains of apples that archaeologists have found from this period are from fruits the same size as the wild apples native to the region. So apples were probably not cultivated in this region 5,000 years ago. The agricultural scientist's argument is most vulnerable to criticism on the grounds that the argument (A) fails to consider that even if a plant was not cultivated in a given region at a specific time, it may have been cultivated in nearby regions at that time" (B) fails to consider that plants that have been cultivated for only a short time may tend to resemble their wild counterparts much more closely than plants that have been cultivated for a long time" (C) takes for granted that all apples are either the size of wild apples or the size of the cultivated apples now found in supermarkets" (D) employs a premise that is incompatible with the conclusion it is supposed to justify" (E) uses a claim that presupposes the truth of its main conclusion as part of the justification for that conclusion
Flawed Reasoning B
Researchers recently studied the relationship between diet and mood, using a diverse sample of 1000 adults. It was found that those who ate the most chocolate were the most likely to feel depressed. Therefore, by reducing excessive chocolate consumption, adults can almost certainly improve their mood. The argument is most vulnerable to criticism on which one of the following grounds? (A) It improperly infers from the fact that a substance causally contributes to a condition that a reduction in the consumption of the substance is likely to eliminate that condition (B) It draws a conclusion about the population as a whole on the basis of a sample that is unlikely to be representative of that population (C) It draws a conclusion about a causal relationship between two phenomena from evidence that merely suggests that there is a correlation between those phenomena (D) It confuses a condition that is necessary for establishing the truth of the conclusion with a condition that is sufficient for establishing the truth of the conclusion (E) Its conclusion is worded too vaguely to evaluate the degree to which the premises support the truth of the conclusion
Flawed Reasoning C
Due to wider commercial availability of audio recordings of authors reading their own books, sales of printed books have dropped significantly. Which one of the following conforms most closely to the principle illustrated above? (A) Because of the rising cost of farm labor, farmers began to make more extensive use of machines. (B) Because of the wide variety of new computer games on the market, sales of high-quality computer video screens have improved.(C) Because a new brand of soft drink entered the market, consumers reduced their consumption of an established brand of soft drink. (D) Because a child was forbidden to play until homework was completed, that child did much less daydreaming and focused on homework. (E) Because neither of the two leading word processing programs has all of the features consumers want, neither has been able to dominate the market.
Give an example: Identify the principle and then find the answer that best represents that principle C
Parents should not necessarily raise their children in the ways experts recommend, even if some of those experts are themselves parents. After all, parents are the ones who directly experience which methods are successful in raising their own children. Which one of the following most closely conforms to the principle that the passage above illustrates? (A) Although music theory is intrinsically interesting and may be helpful to certain musicians, it does not distinguish good music from bad: that is a matter of taste and not of theory. (B) One need not pay much attention to the advice of automotive experts when buying a car if those experts are not interested in the mundane factors that concern the average consumer. (C) In deciding the best way to proceed, a climber familiar with a mountain might do well to ignore the advice of mountain climbing experts unfamiliar with that mountain. (D) A typical farmer is less likely to know what types of soil are most productive than is someone with an advanced degree in agricultural science. (E) Unlike society, one's own conscience speaks with a single voice; it is better to follow the advice of one's own conscience than the advice of society.
Give an example: Identify the principle and then find the answer that best represents that principle C
Ethicist: The most advanced kind of moral motivation is based solely on abstract principles. This form of motivation is in contrast with calculated self interest or the desire to adhere to societal norms and conventions. The actions of which one of the following individuals exhibit the most advanced kind of moral motivation, as described by the ethicist? (A) Bobby contributed money to a local charity during a charity drive at work because he worried that not doing so would make him look stingy. (B) Wes contributed money to a local charity during a charity drive at work because he believed that doing so would improve his employer's opinion of him. (C) Donna's employers engaged in an illegal but profitable practice that caused serious damage to the environment. Donna did not report this practice to the authorities, out of fear that her employers would retaliate against her. (D) Jadine's employers engaged in an illegal but profitable practice that caused serious damage to the environment. Jadine reported this practice to the authorities out of a belief that protecting the environment is always more important than monetary profit. (E) Leigh's employers engaged in an illegal but profitable practice that caused serious damage to the environment. Leigh reported this practice to the authorities only because several colleagues had been pressuring her to do so.
Give an example: Identify the principle and then find the answer that best represents that principle D
It is a principle of economics that a nation can experience economic growth only when a consumer confidence is balanced with a small amount of consumer skepticism. Which one of the following is an application of the economic principle above? A. Any nation in which consumer confidence is balanced with a small amount of consumer skepticism will experience economic growth. B. Any nation in which the prevailing attitude of consumers is not skepticism will experience economic growth. C. Any nation in which the prevailing attitude of consumers is either exclusively confidence or exclusively skepticism will experience economic growth. 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.
Give an example: Identify the principle and then find the answer that best represents that principle D
Goswami: I support the striking workers at Erogon Foods. They are underpaid. The majority of them make less than $20,000 per year. Nordecki: If pay is the issue, I must disagree. The average annual salary of the striking workers at Ergon Foods is over $29,000. Goswami and Nordecki disagree over the truth of which one of the following statements? A) the average annual salary at Ergon Foods is over $29,000. B) Pay is the primary issue over which the workers are striking at Ergon Foods. C) It is reasonable to support striking workers who are underpaid D) The striking workers at Ergon Foods are underpaid E) It was unreasonable for the workers at Ergon Foods to go on strike
Identify the disagreement D
Moralist: TV talk shows are contributing to the moral decline in our country. By constantly being shown the least moral people in our society, viewers begin to think that such people are the norm, and that there is something wrong with being morally upright. TV talk show host: Well, if there is such a decline, it's not because of TV talk shows: we simply show people what they want to see. What can be wrong with letting the viewers decide? Furthermore, if restrictions were put on my show, that would amount to censorship, which is wrong. The moralist's and the TV talk show host's statements provide the most support for holding that they disagree about whether A. TV talk shows should be censored B. people's moral standards have changed C. TV talk shows influence people's conception of what is the norm D. TV talk shows, by presenting immoral guests, are causing a moral decline E. it is wrong not to let the viewers decide what they want to see
Identify the disagreement D
Prosecutor: Dr. Yuge has testified that, had the robbery occurred after 1:50 A.M., then, the moon having set at 1:45 A.M., it would have been too dark for Klein to recognize the perpetrator. But Yuge acknowledged that the moon was full enough to provide considerable light before it set. And we have conclusively shown that the robbery occurred between 1:15 and 1:30 A.M. So there was enough light for Klein to make a reliable identification. The prosecutor's reasoning is most vulnerable to criticism because it overlooks which one of the following possibilities? (A) Klein may be mistaken about the time of the robbery and so it may have taken place after the moon had set. (B) The perpetrator may closely resemble someone who was not involved in the robbery. (C) Klein may have been too upset to make a reliable identification even in good light. (D) Without having been there, Dr. Yuge has no way of knowing whether the light was sufficient. (E) During the robbery the moon's light may have been interfered with by conditions such as cloud cover.
Identify the flaw E
Library preservationist: Due to the continual physical deterioration of the medieval manuscripts in our library's collection, we have decided to restore most of our medieval manuscripts that are of widely acknowledged cultural significance, though this means that some medieval manuscripts whose authenticity is suspect will be restored. However, only manuscripts whose safety can be ensured during the restoration process will be restored, and manuscripts that are not frequently consulted by researchers will not be restored. If all of the library preservationist's statements are true, which one of the following must be true of the medieval manuscripts in the library's collection? (A) Some of the medieval manuscripts whose authenticity is suspect are frequently consulted by researchers (B) All of the medieval manuscripts widely acknowledged to be of cultural significance are manuscripts whose safety can be ensured during the restoration process. (C) All of the medieval manuscripts whose safety can be ensured during the restoration process are frequently consulted by researchers (D) The medieval manuscripts most susceptible to deterioration are those most frequently consulted by researchers (E) None of the medieval manuscripts that are rarely consulted by researchers is widely acknowledged to be of cultural significance
Inference (Must be true) A
Modern science is built on the process of posing hypotheses and testing them against observations—in essence, attempting to show that the hypotheses are incorrect. Nothing brings more recognition than overthrowing conventional wisdom. It is accordingly unsurprising that some scientists are skeptical of the widely accepted predictions of global warming. What is instead remarkable is that with hundreds of researchers striving to make breakthroughs in climatology, very few find evidence that global warming is unlikely. The information above provides the most support for which one of the following statements? (A) Most scientists who are reluctant to accept the global warming hypothesis are not acting in accordance with the accepted standards of scientific debate. (B) Most researchers in climatology have substantial motive to find evidence that would discredit the global warming hypothesis. (C) There is evidence that conclusively shows that the global warming hypothesis is true. (D) Scientists who are skeptical about global warming have not offered any alternative hypotheses to explain climatological data. (E) Research in global warming is primarily driven by a desire for recognition in the scientific community.
Inference: Find an answer that is supported by the info in the passage B
One of the most vexing problems in historiography is dating an event when the usual sources offer conflicting chronologies of the event. Historians should attempt to minimize the number of competing sources, perhaps by eliminating the less credible ones. Once this is achieved and several sources are left, as often happens, historians may try, though on occasion unsuccessfully, to determine independently of the usual sources which date is more likely to be right. Which one of the following inferences is most strongly supported by the information above? (A) We have no plausible chronology of most of the events for which attempts have been made by historians to determine the right date (B) Some of the events for which there are conflicting chronologies and for which attempts have been made by historians to determine the right date cannot be dated reliably by historians. (C) Attaching a reliable date to any event requires determining which of several conflicting chronologies is most likely to be true. (D) Determining independently of the usual sources which of several conflicting chronologies is more likely to be right is an ineffective way of dating events. (E) The soundest approach to dating an event for which the usual sources give conflicting chronologies is to undermine the credibility of as many of these sources as possible.
Inference: Find an answer that is supported by the info in the passage B
It is wrong to waste our natural resources, and it is an incredible water of resources to burn huge amounts of trash in incinerators. When trash is recycled, fewer resources are wasted. Because less trash will be recycled if an incinerator is built, the city should not build incinerator. Which one of the following can be properly inferred from the statements above: (A)All of the city's trash that is not recycled goes into incinerators. (B)By recycling more trash, the city can stop wasting resources entirely. ©The most effective way to conserve resources is to recycle trash. (D)If the city is to avoid wasting resources, huge amounts of trash cannot be burned in any city incinerator. (E)If the city does not burn trash, it will not waste resources
Inference: Find an answer that is supported by the info in the passage D
Economist: Currently, many countries rely primarily on taxing income to fund government expenditures. But taxing income does nothing to promote savings and investment. Taxing consumption, on the other hand, would encourage savings. The most important challenge facing these countries is improving their economies, and the only way to accomplish this is to increase their savings rates. Hence, ________ Which one of the following most logically completes the economist's argument? (A) most governments should stop taxing savings and investment (B) the economies of countries will rapidly improve if their governments adopt tax policies that encourage savings and investment (C) in most countries taxes on consumption alone could raise adequate revenues to fund government expenditures (D) the tax laws of many countries should be revised to focus on taxing consumption rather than income (E) it is detrimental to the economic improvement of any country to continue to tax income
Main Point (fill in blank) D
We should accept the proposal to demolish the old train station, because the local historical society, which vehemently opposes this, is dominated by people who have no commitment to long-term economic well-being. Preserving old buildings creates an impediment to new development, which is critical to economic health. The flawed reasoning exhibited by the argument above is most similar to that exhibited by which one of the following arguments? (A) Our country should attempt to safeguard works of art that it deems to possess national cultural significance. These works might not be recognized as such by all taxpayers, or even all critics. Nevertheless, our country ought to expend whatever money is needed to procure all such works as they become available. (B) Documents of importance to local heritage should be properly preserved and archived for the sake of future generations. For, if even one of these documents is damaged or lost, the integrity of the historical record as a whole will be damaged. (C) You should have your hair cut no more than once a month. After all, beauticians suggest that their customers have their hair cut twice a month, and they do this as a way of generating more business for themselves. (D) The committee should endorse the plan to postpone construction of the new expressway. Many residents of the neighborhoods that would be affected are fervently opposed to that construction, and the committee is obligated to avoid alienating those residents. (E) One should not borrow even small amounts of money unless it is absolutely necessary. Once one borrows a few dollars, the interest starts to accumulate. The longer one takes to repay, the more one ends up owing, and eventually a small debt has become a large one.
Match the flaw C
All unemployed artists are sympathetic to social justice. And no employed artists are interested in the prospect of great personal fame. If the claims made above are true, then which of the following must be true? A) If there are artists interested in the prospect of great personal fame, they are sympathetic to social justice. B) If an artist is sympathetic to social justice, that artist is unemployed. C) All artists uninterested in the prospect of great personal fame are sympathetic to social justice. D) Every unemployed artist is interested in the prospect of great personal fame. E) All artists are either sympathetic to social justice or are interested in the prospect of great personal fame.
Must be true A
Among the many temptations of the digital age, manipulation of photographs has proved particularly troublesome for science. Recently, a journal of cellular biology began using a software tool to examine the digital images submitted along with articles for publication. It discovered that dozens of authors had submitted digital images that had been manipulated in ways that violated the journal's guidelines. Clearly, scientific fraud is a widespread problem among the author submitting to that journal. Which of the following is an assumption required by the argument? (A)The scientists who submitted manipulated images were aware that the journal used software to examine digital images for for evidence of manipulation (B) The journal requires that all articles submitted for publication include digital images (C) Scientific fraud is possible in the field of cellular biology only if the research is documented with digital images (D) Many of the scientists who submitted articles with manipulated images did so in order to misrepresent the information conveyed by those images (E) Scientific fraud is a widespread problem only among scientists who submit articles to journals of cellular biology
Necessary Assumption D
Sanderson intentionally did not tell his cousin about overhearing someone say that the factory would close, knowing that if he withheld this information, his cousin would assume it would remain open. Clearly this was morally wrong. After all, lying is morally wrong. And making a statement with the intention of misleading someone is lying. True, it was Sanderson's failing to state something that misled his cousin. yet there is no moral difference between stating and failing to state if they are done with the same intention. Which one of the following is an assumption required by the argument? (A) Sanderson believed that his cousin would not want to be informed about the factory closing (B) No one ever told Sanderson's cousin about the factory closing (C) Sanderson believed that the factory would in fact be closing (D) Sanderson would have lied to his cousin if his cousin had asked him whether the factory would be closing (E) Sanderson had something to gain by his cousin's continuing to believe that the factory would remain open
Necessary Assumption C
Businesses frequently use customer surveys in an attempt to improve sales and increase profits. However, a recent study of the effectiveness of these surveys found that among a group of businesses that sold similar products, profits declined in most of the businesses that used surveys during the course of the study but not in most of the businesses that did not use any surveys during the course of the study. Which one of the following, if true, most helps to explain why the profits of businesses that did not use customer surveys did not decline while the profits of those that used surveys did decline? (A) When one business increases its profits, its competitors often report a decline in profits (B) Some businesses routinely use customer surveys (C) Most businesses of the kind included in the study generally administer customer surveys only as response to complaints by customers. (D) Customers who complete surveys do not always respond accurately to all the questions on the survey (E) Some of the businesses included in the study did not analyze the results of the customer surveys they conducted.
Paradox C
There are many agricultural regions in North America where the growing season is long enough to allow pumpkin production well into autumn with no risk of frost. Nonetheless, pumpkin production in North America is concentrated in regions with long, cold winters, where the growing season is delayed and pumpkin crops are exposed to risk of damage or destruction by early autumn frosts. Which one of the following, if true, most helps to resolve the apparent discrepancy in the information above? (A) Pumpkins are usually grown to reach maturity in autumn. (B) Pumpkins depend on bees for pollination, and bees are active only in warm weather. (C) More pumpkins are sold to consumers in regions of North America with long growing seasons than to those in regions with short growing seasons. (D) Prolonged cold temperatures kill soil-borne fungus and other sources of disease that would kill or seriously damage pumpkins. (E) Most of the pumpkin seed used by growers in North America is produced in areas where the growing season is long, and plants used for seed production are protected in greenhouses.
Paradox D
The older a country is, the more likely it is to be ruled by a monarch. Thus, since most countries are not ruled by monarchs, if a country is particularly new it is probably not ruled by a monarch. The pattern of reasoning in the argument above is most similar to that in which one of the following arguments? (A) Most novels are not made into movies. However, the more popular a novel is, the more likely it is to be made into a movie. Thus, if a movie is quite unpopular, it was probably not based on a novel. (B) Most novels are not made into movies. However, the more popular a movie is, the more likely it is that the movie was based on a novel. Thus, if a novel is particularly popular, it will probably be made into a movie. (C) Most novels are not made into movies. Moreover, if a novel is particularly unpopular, it will probably not be made into ma movie. Thus, the more popular a novel is, the more likely it is to be made into a movie. (D) Most novels are not made into movies. However, the more popular a novel is, the more likely it is to be made into a movie. Thus, if a novel is quite unpopular, it will probably not be made into a movie. (E) Most novels are not made into movies. Moreover, the more complex a novel's plot, the less likely the novel is to be made into a movie. Thus, if a novel has a particularly simple plot, it will probably be made into a movie.
Parallel Reasoning D
The current theory about earthquakes holds that they are caused by adjoining plates of rock sliding past each other; the plates are pressed together until powerful forces overcome the resistance. As plausible as this may sound, at least one thing remains mysterious on this theory. The overcoming of such resistance should create enormous amounts of heat. But so far no increases in temperature unrelated to weather have been detected following earthquakes. Which one of the following most accurately expresses the main point of the argument? A. No increases in temperature have been detected following earthquakes. B. The current theory does not fully explain earthquake data. C. No one will ever be sure what the true cause of earthquakes is. D. Earthquakes produce enormous amounts of heat that have so far gone undetected. E. Contrary to the current theory, earthquakes are not caused by adjoining plates of rock sliding past one another.
Reasoning Structure: Identify the main point. B
Ethicist: Both ASA and TPA are clot-dissolving agents. Recent studies show that the more expensive agent, TPA, would save at most two more lives than would ASA out of every 50 cardiac patients to whom they are post operatively administered. However, since the relatives of the patients who die simply because they were given the less expensive medicine would be particularly grieved, the financial saving involved in using ASA over TPA must also be weighed against such considerations. Which one of the following most accurately expresses the conclusion of the ethicist's argument? A. ASA should never be given to postoperative cardiac patients in place of TPA. B. TPA is a slightly more effective clot-dissolving agent than ASA. C. The extra expense of TPA cannot be weighed simply against the few additional lives saved. D. SA is a less expensive clot-dissolving agent than TPA. E. Relatives of a patient who has died grieve more if the patient received ASA rather than TPA.
Reasoning Structure: Identify the main point. C
It is well known that many species adapt to their environment, but it is usually assumed that only the most highly evolved species alter their environment in ways that aid their own survival. However, this characteristic is actually quite common. Certain species of plankton, for example generate a gas that is converted in the atmosphere into particles of sulfate. These particles cause water vapor to condense, thus forming clouds. Indeed, the formation of clouds over the ocean largely depends on the presence of these particles. More cloud cover means more sunlight is reflected, and so the earth absorbs less heat. Thus plankton cause the surface of the earth to be cooler and this benefits the plankton. What is the main conclusion of the above statements? (A) Plankton cause the surface of the earth to be cooler. (B) It is well known that many species adapt to their environment (C) The formation of clouds depends on the presence of sulphate particles in the atmosphere. (D) The characteristic of species altering their environment in ways that aid their own survival actually quite common. (E) Certain planktons aid in the formation of clouds Of the following, which one most accurately expresses restated conclusion of the argument? A. The Earth would be far warmer than it is now if certain species of plankton became extinct. B. By altering their environment in ways that improve their chances of survival, certain species of plankton benefit the Earth as a whole. C. Improving their own chances of survival by altering the environment is not limited to the most highly evolved species. D. The extent of the cloud cover over the oceans is largely determined by the quantity of plankton in those oceans. E. Species such as plankton alter the environment in ways that are less detrimental to the well-being of other species than are the alterations to the environment made by more highly evolved species.
Reasoning Structure: Main conclusion/ Main Point D C
Joseph: My encyclopedia says that the mathematician Pierre de Fermat died in 1665 without leaving behind any written proof for a theorem that he claimed nonetheless to have proved. Probably this alleged theorem simply cannot be proved, since---as the article points out---no one else has been able to prove it. Therefore it is likely that Fermat was either lying or else mistaken when he made his claim. Laura: Your encyclopedia is out of date. Recently someone has in fact proved Fermat's theorem. And since the theorem is provable, your claim---that Fermat was lying or mistaken---clearly is wrong. Which one of the following most accurately describes a reasoning error in Laura's argument? (A) It purports to establish its conclusion by making a claim that, if true, would actually contradict that conclusion. (B) It mistakenly assumes that the quality of a person's character can legitimately be taken to guarantee the accuracy of the claims that person has made. (C) It mistakes something that is necessary for its conclusion to follow for something that ensures that the conclusion follows. (D) It uses the term "provable" without defining it. (E) It fails to distinguish between a true claim that has mistakenly between believed to be false and a false claim that has mistakenly been believed to be true.
Reasoning Structure: Understand the role of the statement B
Gamba: Muñoz claims that the Southwest Hopeville Neighbors Association overwhelmingly opposes the new water system, citing this as evidence of citywide opposition. The association did pass a resolution opposing the new water system, but only 25 of 350 members voted, with 10 in favor of the system. Furthermore, the 15 opposing votes represent far less than 1 percent of Hopeville's population. One should not assume that so few votes represent the view of the majority of Hopeville's residents. Of the following, which one most accurately describes Gamba's strategy of argumentation? (A) questioning a conclusion based on the results of a vote, on the grounds that people with certain views are more likely to vote (B) questioning a claim supported by statistical data by arguing that statistical data can be manipulated to support whatever view the interpreter wants to support (C) attempting to refute an argument by showing that, contrary to what has been claimed, the truth of the premises does not guarantee the truth of the conclusion (D) criticizing a view on the grounds that the view is based on evidence that is in principle impossible to disconfirm (E) attempting to cast doubt on a conclusion by claiming that the statistical sample on which the conclusion is based is too small to be dependable
Reasoning structure: Relationship between support and the point. E
It is now a common complaint that the electronic media have corroded the intellectual skills required and fostered by the literary media. But several centuries ago the complaint was that certain intellectual skills, such as the powerful memory and extemporaneous eloquence that were intrinsic to oral culture, were being destroyed by the spread of literacy. So, what awaits us is probably a mere alteration of the human mind rather than its devolution. The reference to the complaint of several centuries ago that powerful memory and extemporaneous eloquence were being destroyed plays which one of the following roles in the argument? (A) evidence supporting the claim that the intellectual skills fostered by the literary media are being destroyed by the electronic media (B) an illustration of the general hypothesis being advanced that intellectual abilities are inseparable from the means by which people communicate (C) an example of a cultural change that did not necessarily have a detrimental effect on the human mind overall (D) evidence that the claim that the intellectual skills required and fostered by the literary media are being lost is unwarranted (E) possible evidence, mentioned and then dismissed, that might be cited by supporters of the hypothesis being criticized
Reasoning structure: What is the role that this part of the argument if playing? C
Scientist: Some colonies of bacteria produce antibiotic molecules called phenazines, which they use to fend off other bacteria. We hypothesize that phenazines also serve as molecular pipelines that give interior bacteria access to essential nutrients in the environment surrounding the colony. Which one of the following, if true, provides the most support for the scientist's hypothesis? (A) Bacteria colonies that do not produce phenazines form wrinkled surfaces, thus increasing the number of bacteria that are in direct contact with the surrounding environn1ent. (B) The rate at which a bacteria colony produces phenazines is determined by the number of foreign bacteria in the environment immediately surrounding the colony. (C) When bacteria colonies that do not produce phenazines are buried in nutrient-rich soil, they grow as quickly as colonies that do produce phenazines. (D) Bacteria colonies that produce phenazines are better able to fend off other bacteria than are bacteria colonies that do not produce phenazines. (E) Within bacteria colonies that produce phenazines, interior bacteria are more likely to die than are bacteria along the edges.
Strengthen A
Direct-mail advertising usually consists of advertisements for products to be purchased from home, so the perception that it is bad for the environment is misguided. Because of direct-mail advertising, millions of people buy products by phone or online - products whose purchase would otherwise require the use of a car, thus adding pollutants to the air. Which one of the following, if true, would most strengthen the argument? (A) Although the primary intent of most direct-mail advertisers is to convince people to buy products from their homes, direct mail can also lead to increased sales in stores by customers who prefer to see a product prior to purchasing it. (B) Most of the products purchased in response to direct-mail advertisements would be purchased even without the direct-mail advertisements. (C) A person who receives and reads a direct-mail advertisement is more likely to purchase the product advertised than is a person who reads an advertisement for a product in a magazine that they subscribe to. (D) Usually, a company that sends out direct-mail advertisements has good reason to think that the person to whom the advertisement is sent would be more interested in the product than would the average person. (E) Products purchased as the result of direct-mail advertising comprise an increasingly large portion of the consumer products purchased each year.
Strengthen B
Literary critic: There is little of social significance in contemporary novels, for readers cannot enter the internal world of the novelist's mind unless they experience that world from the moral perspective of the novel's characters. But in contemporary novels, the transgressions committed by some characters against others are sensationalistic spectacles whose only purpose is to make readers wonder what will happen next, rather than events whose purpose i to be seen as the injustices they are. Which one of the following principles, if valid, would most help to justify the literary critic's argument? (A) An artist who wants to engage the moral sensibilities of his or her audience should not assume that forms of artistic expression that previously served this purpose continue to do so. (B) A novelist who wants to make a reader empathize with a victim of injustice should avoid sensationalistic spectacles whose only purpose is to make readers wonder what will happen next. (C) A work of art is socially important only if it engages the moral sensibilities f its audience (D) If a novel allows a reader to understand injustice from the point of view of its victims, it will be socially significant (E) Novels have social significance only to the extent that they allow readers to enter the internal world of the novelist's mind
Strengthen - Principle E
Commentator: In academic scholarship, sources are always cited, and methodology and theoretical assumptions are set out, so as to allow critical study, replication, and expansion of scholarship. In open-source software, the code in which the program is written can be viewed and modified by individual users for their purposes without getting permission from the producer or paying a fee. In contrast, the code of proprietary software is kept secret, and modifications can be made only by the producer, for a fee. This shows that open-source software better matches the values embodied in academic scholarship, and since scholarship is central to the mission of universities, universities should use only open-source software. The commentator's reasoning most closely conforms to which one of the following principles? (A) Whatever software tools are most advanced and can achieve the goals of academic scholarship are the ones that should alone be used in universities. (B) Universities should use the type of software technology that is least expensive, as long as that type of software technology is adequate for the purposes of academic scholarship. (C) Universities should choose the type of software technology that best matches the values embodied in the activities that are central to the mission of universities. (D) The form of software technology that best matches the values embodied in the activities that are central to the mission of universities is the form of software technology that is most efficient for universities to use. (E) A university should not pursue any activity that would block the achievement of the goals of academic scholarship at that university.
Supporting Principle Question: Bridge the gap between reasoning and conclusion C
It is well known that many species adapt to their environment, but it is usually assumed that only the most highly evolved species alter their environment in ways that aid their own survival. However, this characteristic is actually quite common. Certain species of plankton, for example, generate a gas that is converted in the atmosphere into particles of sulfate. These particles cause water vapor to condense, thus forming clouds. Indeed, the formation of clouds over the ocean largely depends on the presence of these particles. More cloud cover means more sunlight is reflected, and so the Earth absorbs less heat. Thus plankton cause the surface of the Earth to be cooler and this benefits the plankton. Which one of the following accurately describes the argumentative strategy employed? (A) A general principle is used to justify a claim made about a particular case to which that principle has been shown to apply. (B) An explanation of how a controversial phenomenon could have come about is given in order to support the claim that this phenomenon did in fact come about. (C) A generalization about the conditions under which a certain process can occur is advanced on the basis of an examination of certain cases in which that process did occur.( D) A counterexample to a position being challenged is presented in order to show that this position is incorrect. (E) A detailed example is used to illustrate the advantage of one strategy over another.
Understand the reasoning structure D
Advertisement: Auto accidents are the most common cause of whiplash injury, a kind of injury that is caused by a sudden sharp motion of the neck. However, many other types of accidents can produce a sudden sharp motion of the neck and thereby result in whiplash injury. A sudden sharp motion of the neck can be caused by a fall, a bump on the head, or even by being shoved from behind. That is why you should insist on receiving Lakeside Injury Clinic's complete course of treatment for whiplash after any accident that involves a fall or a bump on the head. Which one of the following, if true, provides the strongest basis for criticizing the reasoning in the advertisement? (A) Being shoved from behind rarely causes whiplash. (B) Auto Accidents often involve falling or being bumped on the head (C) Non automobile accidents other than those occasionally cause whiplash injuries (D) It is very uncommon for falling or being bumped on the head to result in a sudden sharp motion of the neck (E) The appropriate treatment for whiplash caused by a fall or a bump on the head is no different from that for whiplash cause by an auto accident
Weaken D
Although video game sales have increased steadily over the past 3 years, we can expect a reversal of this trend in the very near future. Historically, over three quarters of video games sold have been purchased by people from 13 to 16 years of age, and the number of people in this age group is expected to decline steadily over the next 10 years. Which one of the following, if true, would most seriously weaken the argument? (A) Most people 17 years old or older have never purchased a video game. (B) Video game rentals have declined over the past 3 years. (C) New technology will undoubtedly make entirely new entertainment options available over the next 10 years. (D) The number of different types of video games available is unlikely to decrease in the near future. (E) Most of the people who have purchased video games over the past 3 years are over the age of 16.
Weaken: What weakens the support-conclusion relationship? E
We can learn about the living conditions of a vanished culture by examining its language. Thus, it is likely that the people who spoke Proto-Indo-European, the language from which all Indo-European languages descended, lived in a cold climate, isolated from ocean or sea, because Proto-Indo-European lacks a word for "sea," yet contains words for "winter," "snow," and "wolf." Which one of the following, if true, most seriously weakens the argument? (A) A word meaning "fish" was used by the people who spoke Proto-Indo-European. (B) Some languages lack words for prominent elements of the environments of their speakers. (C) There are no known languages today that lack a word for "sea." (D) Proto-Indo-European possesses words for "heat." (E) The people who spoke Proto-Indo-European were nomadic.
Weakens the argument B
