AMC 8 1991 Problem 23

The Pythagoras High School band has $100$ female and $80$ male members. The Pythagoras High School orchestra has $80$ female and $100$ male members. There are $60$ females who are members in both band and orchestra. Altogether, there are $230$ students who are in either band or orchestra or both. The number of males in the band who are NOT in the orchestra is $\text{(A)}\ 10 \text{(B)}\ 20 \text{(C)}\ 30 \text{(D)}\ 50 \text{(E)}\ 70$