FoundationNumeric answer
Hats at a party · Part 1 of 3
People leave their hats at a party and are handed a random hat each on the way out. A derangement is an arrangement in which nobody gets their own hat.
With 4 people, how many ways can the hats be handed back so that nobody gets their own?
Answer with a number. Fractions, powers and expressions like 23/6 or C(52,5) are read correctly in practice.
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