2014 AMC 8 Problem 13

Attempt Problem 13 of the 2014 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 2014 AMC 8 solutions, or check the answer key.

All problems are used with official legal permission of the Mathematical Association of America (MAA).

13.

If nn and mm are integers and n2+m2n^2 + m^2 is even, which of the following is impossible?
nn and mm are even
nn and mm are odd
n+mn + m is even
n+mn + m is odd
none of these are impossible
Answer: D
Concepts:parity
Small hint:
A square has the same parity as its base integer.
Big hint:
For a sum of two squares to be even, the two integers have the same parity.
Solution:
Since n2+m2n^2 + m^2 is even, either n2n^2 and m2m^2 are both odd, or both even.
If they are both odd, then nn and mm are both odd. If they are both even, then nn and mm are both even. If nn and mm are both odd or even, their sum will always be even.
Therefore, n+mn + m is never odd.
Thus, D is the correct answer.
LIVE by Po-Shen Loh
Programs

LIVE Classes

Self-Paced Classes

Stars

Scholarship

About Us

Who Is Po-Shen Loh?

Email Contact

Newsletter

Jobs

Become a Star

For a more Thought Full world.

© 2026 Expii, Inc.