Combinations without repetition

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_{{ 3}}(11) = {{ 11}  choose 3} =  frac{ 11! }{ 3!(11-3)!}  =  frac{ 11  * 10  * 9 } { 3  * 2 }  = 165 $    $

Number of combinations: 165