AMC8 1989 Problem 9

There are 2 boys for every 3 girls in Ms. Johnson’s math class. If there are 30 students in her class, what percent of them are boys?

Answer Choices
A. 12 \%
B. 20 \%
C. 40 \%
D. 60 \%
E. 66 \dfrac{2}{3} \%