餐廳提供15款中式食品和12款西式食品,現有10名人客,每名人客只可選其中一
款中式或西式食品,而他們所選的食品都不相同,最多有2 名人客選西式食品的組
合共有多少個? ans : 487773
請提供計算方法
probability question
2012-01-09 2:44 am
回答 (2)
2012-01-09 3:38 am
✔ 最佳答案
全部客人選中式食品：C(15,10)一名客人選西式食品：C(15,9)C(12,1)
二名客人選西式食品：C(15,8)C(12,2)
總和：C(15,10) + C(15,9)C(12,1) + C(15,8)C(12,2)
= 3003 + 60060 + 424710
= 487773
2012-01-09 3:34 am
(1) No one takes western food = 12C0 x 15C10
(2) 1 person takes western food = 12C1 x 15C9
(3) 2 persons take western food = 12C2 x 15C8
so At most 2 persons take western food = (1) + (2) + (3) = 487773.
(2) 1 person takes western food = 12C1 x 15C9
(3) 2 persons take western food = 12C2 x 15C8
so At most 2 persons take western food = (1) + (2) + (3) = 487773.
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https://hk.answers.yahoo.com/question/index?qid=20120108000051KK01037