# Function combinations Compute the number of ways of picking `k` unordered outcomes from `n` possibilities. Combinations only takes integer arguments. The following condition must be enforced: k <= n. ## Syntax ```js math.combinations(n, k) ``` ### Parameters Parameter | Type | Description --------- | ---- | ----------- `n` | number | BigNumber | Total number of objects in the set `k` | number | BigNumber | Number of objects in the subset ### Returns Type | Description ---- | ----------- number | BigNumber | Number of possible combinations. ### Throws Type | Description ---- | ----------- ## Examples ```js math.combinations(7, 5) // returns 21 ``` ## See also [combinationsWithRep](combinationsWithRep.md), [permutations](permutations.md), [factorial](factorial.md)