1999 AMC 8 Problem 10
Attempt Problem 10 of the 1999 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 1999 AMC 8 solutions, or check the answer key.
All problems are used with official legal permission of the Mathematical Association of America (MAA).
10.
A complete cycle of a traffic light takes seconds. During each cycle the light is green for seconds, yellow for seconds, and red for seconds. At a randomly chosen time, what is the probability that the light will NOT be green?
Answer: E
Small hint:
Not green means red or yellow
Big hint:
Use time not green over total cycle time
Solution:
During a given cycle, the light is not green for seconds.
Then the probability that it is not green is
Thus, E is the correct answer.
Problem 10 in other years
- 1985 AMC 8
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