A certain club has 20 members.What is the ratio of the member of 5-member committees that can be formed from the members of the club to the number of 4-member committees that can be formed from the members of the club?
A.16 to 1 B.15 to 1 C.16 to 5 D.15 to 6 E.5 to 4 各位NN,帮忙解释一下,到底说的是啥?