module 7 practice 1

There are 10 blue, 10 red, and 10 green labels in a bag. The labels are drawn from the bag and not replaced. What is the probability of drawing a blue first, and not blue second to the nearest percent? a) 22% b) 23% c) 32% d) 33%

The correct answer is B. the probaility of blue is 10/30 or 1/3. the probability of not blue second is 20/29 the probabilities are mulitplied together. therefore 1/3 x 20/29 = 0.2298 =0.23 = 23%

There are high school students that are in sports (A) and in band (B). What does A and not B represent? a) Sports only b) Band only c) Both sports and band d) Neither sports nor band.

The correct answer is a. A and not B means only in sports and not in band. Therefore, the students are only in sports.

What is the probability of someone having a birthday in March or December? a) 1/6 b) 1/4 c) 1/3 d) 1/2

The correct answer is a. There are 12 months in the year, and there are 2 months selected. The probability is fraction begin. 2/12 or 1/6

Using the sample space for rolling a die and flipping two coins, what is the probability for an even number and both coins in the same direction? a. 1/4 b. 3/8 c. 1/2 d. 3/4

The correct answer is a. There are three even numbers (2, 4, 6) and there are two possibilities that the coin will be in the same direction. There are 6 total possibilities out of 24 for a probability of 6/24 = 1/4

What is the sample size for choosing an odd number between 1 and 75, including the numbers 1 and 75? a) 37 b) 38 c) 39 d) 40

The correct answer is b. The odd numbers are 1, 3, 5, etc., up to 75. There are 38 odd numbers in the sample space and the sample size is equal to 38.

A survey on favorite pizza topping was given: 33% said cheese was their favorite topping, 25% said pepperoni, 15% said sausage, and 27% said other. If two people are picked at random and replaced, what is the probability of picking two people that like cheese? Round your answer to a whole number. a) 0% b) 11% c) 33% d) 66%

The correct answer is b. The probability is 0.33 for cheese. Since there are 2 people, the probability is multiplied twice. Therefore, (0.33)(0.33) = 0.1089 = 11%

Four cards are chosen from a deck of 52 cards with replacement. A deck contains 13 cards each of spades, hearts, diamonds, and clubs. What is the probability that each of the four cards is a diamond? a. 1/16 b. 1/256 c. 1/28561 d. 1/456976

The correct answer is b. The probability of one diamond is 13/52 or 1/4 Since there are 4 cards drawn, the probability is multiplied 4 times. Therefore 1/4x1/4x1/4x1/4 = 1/256,

The probability that Jimmy attends school on any given day is 0.98. The probability Jimmy misses a day of school, given that he missed the day before, is 0.5. What is the probability that Jimmy misses school on BOTH Tuesday and Wednesday? a) 0.0004 b) 0.01 c) 0.02 d) 0.04

The correct answer is b. These are dependent events, so P(T and W) = P(T) · P (W | T). Here, T represents Jimmy missing school on Tuesday, while W represents Jimmy missing school on Wednesday. The probability of Jimmy missing school on Tuesday, P(T), is 0.02. The probability of Jimmy missing school on Wednesday, given that he missed school on Tuesday, P (W | T), is 0.5. So, P(T and W) = P(T) · P (W | T) = 0.02 · 0.5 = 0.01

Jackie is sick. The probability that she visits the doctor's office is 0.3. The probability that she goes to the doctor's office and gets a new infection while waiting is 0.05. So, if she goes to the doctor's office, what is the probability that she gets an additional infection there? a) 0.015 b) 0.025 c) 0.167 d) 6

The correct answer is c. Let A = Jackie goes to the doctor. Let B = getting a second illness at the doctor's office P(B | A) = P(A and B) ÷ P(A). P(B | A) = 0.05 ÷ 0.3 = 0.167

A survey on favorite pizza topping was given: 33% said cheese was their favorite topping, 25% said pepperoni, 15% said sausage, and 27% said other non-meat topping. If two people are picked at random and replaced, what is the probability of picking two people that like meat? a) 0% b) 10% c) 16% d) 40%

The correct answer is c. The probability is 0.40 the person will choose a meat topping, since 15% liked sausage and 25% liked pepperoni. Since the person picks twice, the probability is multiplied twice. Therefore, (0.40)(0.40) = 0.16 = 16%

A game has a 10-sided fair die. What is the probability of rolling an even number or a number less than 5? a. 1/10 b. 3/10 c. 7/10 d 9/10

The correct answer is c. The probability of an even number is 5/10 and rolling a number less than 5 is 4/1.0. there are 2 values that are even and less than 5 (2 and 4) the probability is 5/10 + 4/10 - 2/10 = 9/10 - 2/10 = 7/10

The numbers 1-10 are in a bag and two are drawn without replacement. What is the probability of drawing an even number first, and a 1 second? a. 1/2 b. 1/9 c. 1/18 d. 1/20

The correct answer is c. The probability of an even number is 5/10 or 1/2 The probability of a 1 for the second number is 1/9 . . The probabilities are multiplied together since both events need to happen. 1/2 x 1/9 =1/18

There are 30 different boxes of cereal to choose from. 6 boxes are red, 5 boxes are yellow, 9 boxes are blue, and 10 boxes are brown. What is the probability of not selecting a red box? a. 3/10 b. 2/3 c. 4/5 d. 5/6

The correct answer is c. There are 24 boxes that are not red. Therefore, the probability is fraction begin. numerator: red.24/30 0r 4/5 the box is not red

There are black, blue, and white marbles in a bag. The probability of choosing a black marble is 0.36. The probability of choosing a black and then a white marble is 0.27. To the nearest hundredth, what is the probability of the second marble being white if the first marble chosen is black? a) 0.27 b) 0.39 c) 0.75 d) 0.86

The correct answer is c. Use P(B | A) = P(A and B)/ P(A) . . The probability of black and white is divided by the probability of black. Therefore, 0.27/0.36 = 0.75

The probability of the Red Sox winning a baseball game is 0.6. The probability of losing the game is 0.4. What is the probability that the Red Sox either win or lose the game? a) 0.12 b) 0.24 c) 0.76 d) 1

The correct answer is d. Winning and losing the game are mutually exclusive events. So, when calculating the probability that the Red Sox win or lose the game, the probability of the union is the sum of the individual probabilities. Here, 0.6 + 0.4 = 1.

There was a marble drawn from a bag in an experiment and placed back in the bag repeatedly. A red marble appeared 45 times, a blue marble 70 times, a green marble 63 times, and a black marble 22 times. What is the empirical probability of the blue marble? a) 0.11 b) 0.225 c) 0.315 d) 0.35

he correct answer is d. The experiment was completed 200 times. There were 70 times a blue marble was drawn so the empirical probability is 70/200 = 0.35.