Combination and Permutation Calculator
Combination and Permutation
Calculate combinations (nCr) and permutations (nPr) for a given n and r
Formula
C(n,r) = n! / (r! x (n-r)!); P(n,r) = n! / (n-r)!
Frequently Asked Questions
What is the difference between combinations and permutations?
Permutations count ordered arrangements (order matters), while combinations count unordered selections (order does not matter). P(n,r) = n!/(n-r)! and C(n,r) = n!/(r!(n-r)!).
When do I use combinations versus permutations?
Use permutations when the order of selection matters (like rankings or codes). Use combinations when order does not matter (like choosing team members or lottery numbers).