Factorial is a function applied to natural numbers greater than zero. The symbol for the factorial function is an exclamation mark after a number, like this: 2!

Formula

n!=1×2×3…×nn!=1×2×3…×n

Where −

·        n!n! = represents factorial

·        nn = Number of sets

Example

Problem Statement:

Calculate the factorial of 5 i.e. 5!.

Solution:

Multiply all the whole numbers up to the number considered.

5!=5×4×3×2×1,=120