2014 AMC 12A Problem 5

On an algebra quiz, 10\% of the students scored 70 points, 35\% scored 80 points, 30\% scored 90 points, and the rest scored 100 points. What is the difference between the mean and median score of the students' scores on this quiz?

\textbf{(A)}\ 1\qquad\textbf{(B)}\ 2\qquad\textbf{(C)}\ 3\qquad\textbf{(D)}\ 4\qquad\textbf{(E)}\ 5

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