概率中开锁问题有两个常见类型:一类是“逐把不重复试开”,另一类是“有放回的随意试开”,下面举例说明开锁问题中概率的求法.例1某人有5把钥匙,只有一把能打开房门锁,但忘记了开门的是哪一把,于是他逐把不重复试开,求恰好第三次打开房门锁的概率.解法1“恰好第三次打开房门锁 There are two common types of unlocking problems in probabilty: one is “try not to repeat the test one by one” and the other is “having a random test that is put back”. Here is an example of how to determine the probability of an unlock problem. Example 1 Someone There are five keys, only one can open the door lock, but forget which one to open the door, so he tried not to repeat the test one by one, seeking the probability of opening the door lock just the third time. Solution 1 "Exactly Three times to open the door lock