6把椅子摆成一排,3人随机就座,任何两人不相邻的坐法种数为( ) A

6把椅子摆成一排,3人随机就座,任何两人不相邻的坐法种数为(  )

A144  B120  C72  D24

答案

D [解析] 这是一个元素不相邻问题,采用插空法,AC24.

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