Combinatorial calculator

Find out how many different ways you can choose k items from n items set. With/without repetition, with/without order.

(n)
(k)

Calculation:

C_k(n) = {n choose k} = frac{ n! }{ k! (n-k)!} $ $ C_{{ 4}}(10) = {{ 10} choose 4} = frac{ 10! }{ 4!(10-4)!} = frac{ 10 * 9 * 8 * 7 } { 4 * 3 * 2 * 1 } = 210 $ $

Number of combinations: 210