Track / Stage 4 / 66 of 340 #326 of 1964

Problem 326

AMC 12 late, AIME early

Algebra Difficulty 4.6 Multiple choice

Set
$A=\{1,3,5,7\}, B=\{2,4,6,8,20\} \text {. }$

If $C=\{s \mid s=a+b, a \in A, b \in B\}$ , then the number of elements in set $C$ is:

Pick one

Official solution

-1. B.
Note that $s$ is odd, with a minimum value of 3 and a maximum value of 27, and it is missing 17 and 19. Therefore, set $C$ has a total of 11 elements.

Source: NuminaMath-1.5, licensed Apache-2.0. Statement reproduced verbatim; metadata (topic, difficulty, ordering) added by this project.