1961 AHSME Problem 15

If x men working x hours a day for x days produce x articles, then the number of articles (not necessarily an integer) produced by y men working y hours a day for y days is:

\textbf{(A)}\ \frac{x^3}{y^2}\qquad \textbf{(B)}\ \frac{y^3}{x^2}\qquad \textbf{(C)}\ \frac{x^2}{y^3}\qquad \textbf{(D)}\ \frac{y^2}{x^3}\qquad \textbf{(E)}\ y

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