1990 AMC 8 Question 9

The grading scale shown is used at Jones Junior High. The fifteen scores in Mr. Freeman’s class were: $89,$ $72,$ $54,$ $97,$ $77,$ $92,$ $85,$ $74,$ $75,$ $63,$ $84,$ $78,$ $71,$ $80,$ $90.$

A $93\text{--}100$ B $85\text{--}92$ C $75\text{--}84$ D $70\text{--}74$ F $0\text{--}69$

In Mr. Freeman’s class, what percent of the students received a grade of C?