1952 AHSME Problem 16

If the base of a rectangle is increased by 10\% and the area is unchanged, then the altitude is decreased by:

\textbf{(A) \ }9\% \qquad \textbf{(B) \ }10\% \qquad \textbf{(C) \ }11\% \qquad \textbf{(D) \ }11\frac{1}{9}\% \qquad \textbf{(E) \ }9\frac{1}{11}\%

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