1950 AHSME Problem 36

A merchant buys goods at 25\% off the list price. He desires to mark the goods so that he can give a discount of 20\% on the marked price and still clear a profit of 25\% on the selling price. What percent of the list price must he mark the goods?

\textbf{(A)}\ 125\%\qquad\textbf{(B)}\ 100\%\qquad\textbf{(C)}\ 120\%\qquad\textbf{(D)}\ 80\%\qquad\textbf{(E)}\ 75\%

Full credit goes to MAA for authoring these problems. These problems were taken on the AOPS website.