Question

Sylvia's grades in the final 2 exams are 82 and 87. What grades must her last exam to obtain an average of no less than 85 in that marking period?

Answer 1

let the grades she get in the final be x
we want average of at least 85
so (x+82+87)/3>=85
(x+169)>=255
x>=86
so she should get at least 86 in the last exam to get average of at least 85