Priors

Counting and complements · Office party

Nobody draws themselves

10 friends write their names on slips, put them in a hat, and each draws one slip at random for Secret Santa. What is the probability that nobody draws their own name?

Answer with a probability. First lock in a gut guess with an 80% range, then solve it properly, then watch a simulation settle on the truth.

Play it

More in counting and complements

All puzzles