Question custom

3.5 Probability & Conditional Probability - Simple probability
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Customer Purchases at a Gas Station
 Beverage purchasedBeverage not purchasedTotal
Gasoline purchased602585
Gasoline not purchased351550
Total9040135

On Tuesday, a local gas station had 135 customers. The table above summarizes whether or not the customers on Tuesday purchased gasoline, a beverage, both, or neither. Based on the data in the table, what is the probability that a gas station customer selected at random on that day did not purchase gasoline?

A.

15 over 50

B.

15 over 40

C.

35 over 50

D.

50 over 135

Customer Purchases at a Gas Station Beverage purchased Beverage not purchased Total Gasoline purchased 60 25

Medium-difficulty · SAT Math · Probability & Conditional Probability — Simple probability. Read the question above, select your answer, and check the full explanation below to understand exactly why the correct choice works.

Answer explanation

Choice D is correct. The total number of gas station customers on Tuesday was 135. The table shows that the number of customers who did not purchase gasoline was 50. Finding the ratio of the number of customers who did not purchase gasoline to the total number of customers gives the probability that a customer selected at random on that day did not purchase gasoline, which is 50 over 135.

Choice A is incorrect and may result from finding the probability that a customer did not purchase a beverage, given that the customer did not purchase gasoline. Choice B is incorrect and may result from finding the probability that a customer did not purchase gasoline, given that the customer did not purchase a beverage. Choice C is incorrect and may result from finding the probability that a customer did purchase a beverage, given that the customer did not purchase gasoline.