AMC 12 2001 Problem 4

The mean of three numbers is $10$ more than the least of the numbers and $15$ less than the greatest. The median of the three numbers is $5$. What is their sum?

$\text{(A)}\ 5 \text{(B)}\ 20 \text{(C)}\ 25 \text{(D)}\ 30 \text{(E)}\ 36$