Question

7. On a recent math test, the boys averaged

81 and the girls averaged 90. If there are twice
as many boys in the class as girls, what was
the overall average for the class?

Answer 1

“Since the actual number of girls and boys is irrelevant, suppose there is one girl and two boys.

Since the actual scores are also irrelevant, suppose that the two boys got the same score.

Then the girl got a 90 and the two boys got 81 each and

(81 + 81 + 90)/3 = 252/3 = 84.”