2000 AMC 10 Problem 8

At Olympic High School, \frac{2}{5} of the freshmen and \frac{4}{5} of the sophomores took the AMC 10. Given that the number of freshmen and sophomore contestants was the same, which of the following must be true?

\textbf{(A) } There are five times as many sophomores as freshmen.

\textbf{(B) } There are twice as many sophomores as freshmen.

\textbf{(C) } There are as many freshmen as sophomores.

\textbf{(D) } There are twice as many freshmen as sophomores.

\textbf{(E) } There are five times as many freshmen as sophomores.

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