Permutation and Combination is difficult?
2016-01-07 4:32 pm
5 cards are drawn from 1 pack of 52 playing cards. Find the number of ways the cards could be drawn if it contains exactly 1 pair
回答 (1)
2016-01-07 5:21 pm
The number of ways
= C(13,1) C(4,2) C(12,3) C(4,1) C(4,1) C(4,1)
= 1098240
1 pair is drawn from A, 2, 3, 4, 5, 6, 7, 8, 9, 10, J, Q, K = C(13,1) C(4,2)
If 1 pair is A,A
then another 3 cards are drawn from 2, 3, 4, 5, 6, 7, 8, 9, 10, J, Q, K = C(12,3) C(4,1) C(4,1) C(4,1)
= C(13,1) C(4,2) C(12,3) C(4,1) C(4,1) C(4,1)
= 1098240
1 pair is drawn from A, 2, 3, 4, 5, 6, 7, 8, 9, 10, J, Q, K = C(13,1) C(4,2)
If 1 pair is A,A
then another 3 cards are drawn from 2, 3, 4, 5, 6, 7, 8, 9, 10, J, Q, K = C(12,3) C(4,1) C(4,1) C(4,1)
收錄日期: 2021-04-23 23:44:06
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20160107083244AARQU5m