Question

Sam scored 43, 48, and 42 points on three tests. How many points should he get on the fourth test to get an average score of 50?

Answer 1

`(43+48+42+x)/(4)=50 \ \ \ |*4 \\ \\ 133+x=200 \\ \\ x=67`

Answer 2

Average score of 50 points from 4 test require cumulative 200 points. 50*4 = 200.
Sam already scored 43 + 48 + 42 points, so he scored 133 points.

In order to hit cumulative 200, he need to score 200 - 133 = 67 points on the forth test.