Suppose there are n people in an office. At Christmas they have a random gift exchange in which every name is writen on scraps of paper, mixed around in a hat, and then everyone draws a name at random to determine who they are to get a gift for.

What is the probability nobody draws their own name?

The required probability is approximately equal to 1/e, whose approximate numerical value is 0.3679.

Posted by K Sengupta on 2022-05-09 21:30:41