Combinations and permutations
How many ways to choose or arrange k items from n, with and without repetition.
- Permutations
- Combinations
- Factorials
Counting
Combinations C(n, k)13,983,816order does not matter, no repetition, a lottery draw
Permutations P(n, k)10,068,347,520order matters, no repetition, a podium finish
Combinations with repetition25,827,165order does not matter, repeats allowed
Permutations with repetition13,841,287,201order matters, repeats allowed, a PIN code
Probability of one specific combination1 in 13,983,816 (0.0000071511%)
n factorial608281864034267560872252163321… (63 digits)