### Atom - `c`

- Combinations

Characters: `c`

Tags: `math` , `number` , `vectorize` , `combinatorics`

##### Arity: dyadic

This atom is dyadic, which means it takes two arguments.

##### Functionality

Return `xCy`

(the number of ways of choosing `y`

out of `x`

objects).

##### Details

`xCy`

is the number of ways to select `y`

objects out of a set of `x`

objects, where the order does not matter. This can be represented as `x! / [ y! (x - y)! ]`

.