TTGWD4-5

Q5:

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

Answer: C

这道题不是这样做么：c20里选5除以c20里选4

，怎么算不对呢？

鼎by myself

C(5,20)/C(4,20)=16/5