Question

Jims 2nd test score was 8 points higher than his 1st tests score his 3rd score was 88.he had a 'B' average (between 80 and 89, inclusive ) for the 3 test what can you conclude about his first test score? it was between?

Answer 1

it would be lower

Answer 2

Let x represents the score on the first test
Then, the score on the second test was x+8
His average for all 3 tests was (x + x+8 + 88)/3=(2x+96)/3
I would use inequality to be faster...
80≤(2x+96)/3≤89
Now solve for x:
(80*3-96)/2≤x≤(89*3-96)/2
72≤x≤85.5
So, his first test score was between 72 and 85.5 inclusive