AMC 12 2011b Problem 21

The arithmetic mean of two distinct positive integers $x$ and $y$ is a two-digit integer. The geometric mean of $x$ and $y$ is obtained by reversing the digits of the arithmetic mean. What is $|x - y|$?

\textbf{(A)}\ 24 \textbf{(B)}\ 48 \textbf{(C)}\ 54 \textbf{(D)}\ 66 \textbf{(E)}\ 70