某人写了6封不同的信,欲寄往6个不同的地址,现将这6封信随意地放进6个具有不同地址的信封里,求恰有2封信放对信封的概率。 用r编写简单函数计算
时间: 2024-02-24 09:55:49 浏览: 166
这个问题可以使用排列组合的方法求解。首先,在6个信中选出2个信件放对信封,然后将这2封信件的地址随意排列,其余4封信件也随意排列,最后求出所有排列的总数。而总的方案数为6的阶乘。因此,恰好有2封信放对信封的概率为:
```
p <- choose(6, 2) * factorial(2) * factorial(4) / factorial(6)
p
```
输出结果为0.03333333,即约为3.33%。
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