2009 AMC 8 Problem 13
Attempt Problem 13 of the 2009 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 2009 AMC 8 solutions, or check the answer key.
All problems are used with official legal permission of the Mathematical Association of America (MAA).
13.
A three-digit integer contains one of each of the digits and What is the probability that the integer is divisible by
Answer: B
Small hint:
A number is divisible by exactly when its last digit is or
Big hint:
With digits and each digit is equally likely to be last.
Solution:
The number is equally likely to end in or
It is divisible by only if the last digit is which happens with probability
Thus, B is the correct answer.
Problem 13 in other years
- 1985 AMC 8
- 1986 AMC 8
- 1987 AMC 8
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- 1989 AMC 8
- 1990 AMC 8
- 1991 AMC 8
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