Question

In how many ways a committee of 5 members to be formed out of 6 boys and 4 girls, if:
a) two girls are included in the committee
b) at least 2 girls in the committee

Answer 1

a) npr=n!/(n-r)!
n=4,r=2
4!/(4-2)!
24/2!
24/2=12 arrangement can be done for girls
n=6,r=3
npr=6!/(6-3)!
720/6=120 arrangements can done for girls