# Combination (mathematics)

In general, the number of combinations of k objects from n objects, written as ${\displaystyle nCk}$ or ${\displaystyle {\tbinom {n}{k}}}$,[1] is equal to ${\displaystyle {\tfrac {n!}{k!(n-k)!}}}$, where "!" stands for the factorial notation. This number is also known as the binomial coefficient.[2][3]