SOLUTION: Tom's average grade is 90. If he received the following grades in all his other subjects, what was his math grade? English: 84; History: 91; Science: 89; Spanish: 95

Algebra ->  Average -> SOLUTION: Tom's average grade is 90. If he received the following grades in all his other subjects, what was his math grade? English: 84; History: 91; Science: 89; Spanish: 95      Log On


   

Question 906359: Tom's average grade is 90. If he received the following grades in all his other subjects, what was his math grade? English: 84; History: 91; Science: 89; Spanish: 95
Found 2 solutions by AlgebraLady88, swincher4391:
Answer by AlgebraLady88(44) About Me  (Show Source):
You can put this solution on YOUR website!
Here, we are primarily interested in finding averages.
We are told that Tom's average grade is 90 and then the subjects with his grades are listed. Here is how we find his Math grade:
(English + History + Science + Spanish + Math) / 5 = 90
(84+ 91+ 89 + 95 + Math) /5 = 90
(359 + Math)/5 = 90
Cross multiplying gives us 359 + Math = 90*5
359 + Math = 450
Math = 450 - 359
Math = 91

Answer by swincher4391(1107) About Me  (Show Source):
You can put this solution on YOUR website!
(e+h+s+p+m) / 5 = 90
(84+91+89+95+m) /5 = 90
(84+91+89+95+m) = 450
(359 + m) = 450
m = 91