Combinatorial calculator

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

Calculation:

C_{k} (n) = (\binom{n}{k}) = \frac{n!}{k! (n - k)!} n = 10 k = 4 C_{4} (10) = (\binom{10}{4}) = \frac{10!}{4! (10 - 4)!} = \frac{10 \cdot 9 \cdot 8 \cdot 7}{4 \cdot 3 \cdot 2 \cdot 1} = 210