1990 AJHSME Problems/Problem 9

Problem

The grading scale shown is used at Jones Junior High. The fifteen scores in Mr. Freeman's class were: \[\begin{tabular}[t]{lllllllll} 89, & 72, & 54, & 97, & 77, & 92, & 85, & 74, & 75, \\ 63, & 84, & 78, & 71, & 80, & 90. & & & \\ \end{tabular}\]

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

\[\boxed{\begin{tabular}[t]{cc} A: & 93 - 100 \\ B: & 85 - 92 \\ C: & 75 - 84 \\ D: & 70 - 74 \\ F: & 0 - 69  \end{tabular}}\]

$\text{(A)}\ 20\% \qquad \text{(B)}\ 25\% \qquad \text{(C)}\ 30\% \qquad \text{(D)}\ 33\frac{1}{3}\% \qquad \text{(E)}\ 40\%$

Solution

We just count to find that there are $5$ students in the $\text{C}$ range.

There are $15$ total, so the percentage is $\frac{5}{15}=33\frac{1}{3}\%$ $\rightarrow \boxed{\text{D}}$.

See Also

1990 AJHSME (ProblemsAnswer KeyResources)
Preceded by
Problem 8
Followed by
Problem 10
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All AJHSME/AMC 8 Problems and Solutions

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