[計量] 請教大家一題關於排列組合的數學問題

看板GRE作者andrew916829 (coolman)時間11年前 (2012/12/29 17:06)推噓10(10推 0噓 12→)

留言22則, 12人參與討論串1/1

There are four balls of different colours and four boxes of the same four colours. The balls have to be put in the boxes of matching colours. What is the probability that all the four balls are not put in the right box? A. 1/24 B. 1/4 C. 1/2 D. 2/3 E. 23/24 我一開始覺得答案沒錯(E)用反面解,1-(均中)=23/24 但後來越想越不對,因為似乎沒考慮到(一對三錯,兩對兩錯似乎也被我加進去了然而題目似乎要問全部放錯的機會,我用暴力解直接排共九種但似乎沒答案........... 請各方神手解惑 -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 220.136.37.160

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adrianx94

12/30 01:36, , 1^F

12/30 01:36, 1^F

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gmtest

12/30 06:50, , 2^F

12/30 06:50, 2^F

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gmtest

12/30 06:51, , 3^F

12/30 06:51, 3^F