Problem:
The grading scale shown is used at Jones Junior High. The fifteen scores in Mr. Freeman's class were:
89,72,54,97,77,92,85,74,75,63,84,78,71,80,90.
In Mr. Freeman's class, what percent of the students received a grade of C?
GradeABCDF​Range93–10085–9275–8470–740–69​​
Answer Choices:
A. 20%
B. 25%
C. 30%
D. 3331​%
E. 40%
Solution:
Five of the fifteen scures [77,75,84,78,80] are in the "C range", so the desired percent is 155​=31​=3331​%.
Answer: D​.
The problems on this page are the property of the MAA's American Mathematics Competitions