2007 AMC 8 Problem 10
Attempt Problem 10 of the 2007 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 2007 AMC 8 solutions, or check the answer key.
All problems are used with official legal permission of the Mathematical Association of America (MAA).
10.
For any positive integer define to be the sum of the positive factors of For example, Find
Answer: D
Small hint:
Apply the boxed operation once to first.
Big hint:
Then apply the same sum-of-factors operation to the result.
Solution:
First, we find that since is prime. Then we need to find The factors of are Adding these yields
Thus, D is the correct answer.
Problem 10 in other years
- 1985 AMC 8
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