Question

Currently, you have a 90, 78, 88, and an 80 on your

tests in math. What do you need to make on the next test
in order to get an average of an 85?.

Answer 1

After next test you will have passed 5 tests. In order to get 85 on avarage you should have total 85*5 scores = 425. Subtract already gained scores`

425-(90+78+88+80) = 89. So You should get 89 on your next test to achieve 85 score avarage.