# Combinations without Repetition

Calculation of possible combinations without repetition

## Function for calculating possible combinations

This function calculates the number of possible combinations from a set without repetition. When combining without repeating, a number k is selected from the total n.

Calculate combinations

 Input Total quantity n Selection k Result

## Description of combinations without repetition

The number of possible combinations from a set without repetition is calculated. In the case of combinations without repetition, a number k is selected from the total n.

The order of the selected objects is ignored. Each object may only be selected once in the object group, i.e. without repetition. For the urn model, this corresponds to a no-replacement, no-order draw.

The formula is:

$$\displaystyle \frac{n!}{(n-k)! · k!}$$

This example shows how many groups with 2 objects from the digits 1 to 3 can be formed. They are the groups (1,2), (1,3) and (2,3). So three groups.