An arithmetic student needs at least a 70% average to receive credit for the course. If she scored 85%, 79%, and 69% on the first three exams, what is the lowest score she can get on the fourth exam to receive credit for the course?
A) 47%
B) 49%
C) 45%
D) 52%

Question

Quizplus · Accepted Answer

The student needs an average of 70% on four exams to receive credit for the course. The student has already taken three exams and scored 85%, 79%, and 69%. The average of these three scores is (85 + 79 + 69) / 3 = 77.67%. To receive credit for the course, the student needs to score at least (70 - 77.67) * 100 / (100 - 77.67) = 47.33% on the fourth exam. The lowest score the student can get on the fourth exam to receive credit for the course is 47%.

An Arithmetic Student Needs at Least a 70% Average to Receive