Question

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 ears on the last exam to get an average
of no less than 80 for the marking period?

Answer 1

84 or more on the third exam.

Explanation:

Since we know the first two scores of the exam, which would be 75 + 81 = 156. We want to find an average that should equal 80 or more.

We get the following setup.

(75 + 81 + x) / 3 >= 80

We want to find the value of x that is the ideal score to get an average of 80 out of all the scores.

(156 + x) / 3 >= 80

156 + x >= 240

x = 84