AMC 12 2018a Problem 1

A large urn contains $100$ balls, of which $36 \%$ are red and the rest are blue. How many of the blue balls must be removed so that the percentage of red balls in the urn will be $72 \%$? (No red balls are to be removed.)

\textbf{(A)}\ 28 \textbf{(B)}\ 32 \textbf{(C)}\ 36 \textbf{(D)}\ 50 \textbf{(E)}\ 64