Suppose ‘n’ people go to a party and leave their hats at the door. At

Suppose ‘n’ people go to a party and leave their hats at the door. At

Suppose ‘n’ people go to a party and leave their hats at the door. At the end of the party, each person picksup a hat at random. Assume each assignment of hats to persons is equally likely. What is the expectednumber of people that get their own hats back?