2009 AMC 8 Problem 10
Attempt Problem 10 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).
10.
On a checkerboard composed of unit squares, what is the probability that a randomly chosen unit square does not touch the outer edge of the board?
Answer: D
Small hint:
Only the squares strictly inside the border do not touch the edge.
Big hint:
An board has a interior.
Solution:
There are squares on the interior.
This means that the probability of choosing one of these squares is
Thus, D is the correct answer.
Problem 10 in other years
- 1985 AMC 8
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