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 Question from penny, a student: What is factorial? For eg. Like 2!, 3! 4! Etc.

Hi Penny,

For any positive integer the factorial of that integer is the product of all positive integers less than or equal to the original integer. Thus foe example $3! = 3 \times 2 \times 1 = 6$ and $5! = 5 \times 4 \times 3 \times 2 \times = 120.$ By convention we also say that $0! = 1.$

I hope this helps,
Penny

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