PSAT Math Multiple-Choice Question 511: Answer and Explanation

Question: 511

Number of Times Jolly Retrieved the Toy Throughout the Day

	9 a.m.	12 p.m.	3 p.m.	6 p.m.
Stuffed Animal	10	8	13	14
Ball	9	15	11	7

The two-way table above shows the number of times Jolly the puppy will retrieve a ball or a stuffed animal at different times of the day. What was the average number of times Jolly retrieved the stuffed animal throughout the day?

• A. 10.50
• B. 10.88
• C. 11.25
• D. 11.50

Correct Answer: C

Explanation:

C

The question asks for the average of a set of numbers. Since the question only refers to the stuffed animal, refer to the top row of data values in the two-way table. For averages, use the formula T = AN, in which T is the total, A is the average, and N is the number of things. Calculate the total of the original set of numbers. The Total is 10 + 8 + 13 + 14 = 45 and the Number of things is 4, so 45 = A(4). Divide both sides by 4 to find that A = 11.25. The correct answer is (C).