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Formulas for Combinations and Permutations

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The Factorial
Formulas for Combinations and Permutations

Factorial Formula

C.K.Taylor

The factorial is a convenient shorthand way to write the product of several consecutive positive whole numbers. The formula for the factorial can be seen above. By convention we define 0! = 1.

As we will see, other formulas dealing with counting build upon the factorial formula.

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