2001 Cayley Problem 4

In a school, 30 boys and 20 girls entered the Cayley competition. Certificates were awarded to 10\% of the boys and 20\% of the girls. Of the students who participated, the percentage that received certificates was

\textbf{(A)}\ 14\quad \textbf{(B)}\ 15\quad \textbf{(C)}\ 16\quad \textbf{(D)}\ 30\quad \textbf{(E)}\ 50

If there are no answer choices shown, enter a numerical answer.

Full credit to this problem is given to the CEMC, you may view all Cayley contests here.