2001 AMC 10 Problem 7

When the decimal point of a certain positive decimal number is moved four places to the right, the new number is four times the reciprocal of the original number. What is the original number?

\textbf{(A) } 0.0002 \qquad\textbf{(B) } 0.002 \qquad\textbf{(C) } 0.02 \qquad\textbf{(D) } 0.2 \qquad\textbf{(E) } 2

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