题库搜索>问题求解PS-13512
If a code word is defined to be a sequence of different letters chosen from the 10 letters A, B, C, D, E, F, G, H, I, and J, what is the ratio of the number of 5-letter code words to the number of 4-letter code words?
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分析B选项
分析C选项
分析D选项
分析E选项
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当前版本由 weeklyup 更新于2017-08-25 21:02:04 感谢由 weeklyup 对此题目的解答所做出的贡献。C(10,5)/C(10,4)=6/1
是A(10,5)/A(10,5)=6/1
angelababy0303
C(10,5)/C(10,4)算出来不是等于6:5么......
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2022-09-03 18:10:10
Cavaliers
是排列不是组合 P（10，5）/P(10，4)=（10！/5！）/（10！/6！）=6/1
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2020-10-11 17:07:16
C韵
应是A(10.5) / A(10,4)=6/1
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2019-01-13 12:15:01
细胞周期
C(10,5)/C(10,4)算出来明明是6：5好不好，应该用A
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2018-10-15 10:16:45
asdf
排列不是组合
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2018-02-20 00:15:31
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