in how many ways could ten questions on a test be arranged,if the easiest question and the most difficult questiona) are side by sideb) are not side by sidethanks

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in how many ways could ten questions on a test be arranged,if the easiest question and the most difficult questiona) are side by sideb) are not side by sidethanks
in how many ways could ten questions on a test be arranged,if the easiest question and the most difficult question
a) are side by side
b) are not side by side
thanks

in how many ways could ten questions on a test be arranged,if the easiest question and the most difficult questiona) are side by sideb) are not side by sidethanks
题目翻译:
十到题目在一次测试中如何安排,如果最容易和最难的问题:
a)并排相邻
b)不相邻
a)最容易和最难的问题相邻
这两个问题先作为单独考虑排列,它俩排列有2!
再将它俩作为一个整体,和其他八个一同排列,那么就是9!
那么此问题答案就是2!*9!
b)最容易和最难的问题不相邻
那么用全部排列方式-相邻时的方式就可以了.
答案:10!-2!*9!