# Combine

Combine-func

## Description

This function is used to calculate the number of k-combinations from a given set with n elements, denoted by:

Please note that a combination is different from a permutation in which the combination is a set of elements regardless of the internal order, while the internal order in a permutation is significant. For example, in the 3 elements of "a, b, c", "ab" and "ba" are considered the same combination but two different permutations.

## Syntax

double Combine(int n, int k)

## Parameters

**n**

- The number of elements in a given set. It must be a positive integer.

**k**

- The k-combinations. It must be a positive integer and
**k** < **n**.

## Return

Return the number of k-combinations from a given set with n elements

## Example

combine(4, 2) = ; // returns 6
Combine(8, 2) = ; // returns 28

## See Also

Combina, Permut, Permutationa