Track / Stage 4 / 118 of 340 #378 of 1964

Problem 378

AMC 12 late, AIME early

Algebra Difficulty 4.7 Find the answer

1. Let set $A=\{2,0,1,8\}, B=\{2 a \mid a \in A\}$ , then the sum of all elements in $A \cup B$ is

Your answer

A number or a short expression. Spacing and $ signs are ignored.

Official solution

Answer: 31.
Solution: It is easy to know that $B=\{4,0,2,16\}$ , so $A \cup B=\{0,1,2,4,8,16\}$ . The sum of all elements in $A \cup B$ is $0+1+2+4+8+16=31$ .

Source: NuminaMath-1.5, licensed Apache-2.0. Statement and solution reproduced as published; topic, difficulty and ordering added by this site.