Question

Jim has received scores of

75
and
81
on his first two 100 point tests.
What score must he get on his third 100 point test to keep an average of
84
or greater?

Answer 1

t ≥ 96 test score must be 96 or greater

Explanation:

Let t - score on his third test

(75 + 81 + t) ÷ 3 ≥ 84

⇒ (75 + 81 + t) ≥ 84 x 3

⇒ (75 + 81 + t) ≥ 252

⇒ 156 + t ≥ 252

⇒ t ≥ 252 - 156 ≥ 96