Question

Are all factorials even? If then, give an example.

Answer 1

Answer:

One factorial is one. But zero factorial also is equal to one. The factorial of every number greater than one will contain at least one multiple of two, so all other factorials are even. Zero factorial also is one, that's why the answer is no. But if we change the question as “Are the factorials of any number other than zero and one even?” or “Are the factorials of every number greater than one even?” the answer will be yes. Note that factorial is defined only for whole numbers, not negative numbers and fractions.