1955 AHSME Problem 7

If a worker receives a 20% cut in wages, he may regain his original pay exactly by obtaining a raise of:

\textbf{(A)}\ \text{20\%}\qquad\textbf{(B)}\ \text{25\%}\qquad\textbf{(C)}\ 22\frac{1}{2}\text{\%}\qquad\textbf{(D)}\ \${20}\qquad\textbf{(E)}\ \${25}

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