SOLUTION: There are three exams in a marking period. A student received grades of 75 and 81 on the first two exams. What grade must the student earn on the last exam to get an average of no

Algebra ->  Inequalities -> SOLUTION: There are three exams in a marking period. A student received grades of 75 and 81 on the first two exams. What grade must the student earn on the last exam to get an average of no       Log On


   

Question 1090529: There are three exams in a marking period. A student received grades of 75 and 81 on the first two exams. What grade must the student earn on the last exam to get an average of no less than 80 for the marking period.
Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
(75+81+x)/3=80
75+81+x=240
156+x=240
x=84
another way
75+81
80-75=+5
80-81=-1
+5-1=4
80+4=84