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?
16 to 1
15 to 1
16 to 5
15 to 6
5 to 4
C(5,20)/C(4,20)
此题问的是从二十个人里选出五人一组的分法个数/从二十个人里选出四人一组的分法个数
5c20除以4c20
好吧 读错题目了。。。
答案错了吧