# Function permutations #

Compute the number of ways of obtaining an ordered subset of `k`

elements
from a set of `n`

elements.

Permutations only takes integer arguments. The following condition must be enforced: k <= n.

## Syntax #

```
math.permutations(n)
math.permutations(n, k)
```

### Parameters #

Parameter | Type | Description |
---|---|---|

`n` |
number | BigNumber | The number of objects in total |

`k` |
number | BigNumber | The number of objects in the subset |

### Returns #

Type | Description |
---|---|

number | BigNumber | The number of permutations |

### Throws #

Type | Description —- | ———–

## Examples #

```
math.permutations(5) // 120
math.permutations(5, 3) // 60
```