1.a football team has 17 members. among them, 3 are goalkeepers. in how many ways can 7 members chosen to include 1 goalkeeper?
2.5cards are selected from a pack of 52 playing cards. how many combinations are there if all the cards selected are of the same suit?
Permutation!
2011-01-28 7:05 am
回答 (1)
2011-01-28 7:12 am
✔ 最佳答案
1)Chose 1 goalkeeper first , 3C1 = 3 ways ,then chose 6 members from other 17-3 = 14 members ,
14C6 = 3003 ways ,3 * 3003 = 9009 ways.#
2)There are 4 suits.For any 1 suit , 13C5 = 1287 combinations,4 x 1287 = 5148 combinations. #
收錄日期: 2021-04-21 22:18:27
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20110127000051KK01289