1991 AMC 8 Problem 22
Attempt Problem 22 of the 1991 AMC 8 below, then check your answer against the professionally curated solution from LIVE by Po-Shen Loh. You can also try the full timed exam, view all 1991 AMC 8 solutions, or check the answer key.
All problems are used with official legal permission of the Mathematical Association of America (MAA).
22.
Each spinner is divided into equal parts. The results obtained from spinning the two spinners are multiplied. What is the probability that this product is an even number?
Answer: D
Small hint:
A product is even unless both spun numbers are odd
Big hint:
Find the probability of an odd product (odd times odd), then subtract from
Solution:
The product is odd only when both numbers are odd. The first spinner is odd ( or ) with probability and the second is odd () with probability
So the product is odd with probability and even with probability
Thus, the correct answer is D .
Problem 22 in other years
- 1985 AMC 8
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