Number of Permutations with No Repetition

Number of Permutations with No Repetition

## Formula

The number of ways to arrange $$r$$ distinct objects selected from $$n$$ distinct objects is:

$${}^nP_r=\frac{n!}{(n-r)!}$$

## Conditions / Special Cases

Repetition is not allowed, so each object can be used at most once.

## Usage

- Used for arrangements where every selected object is distinct.