Permutation & Combination Calculator (nPr, nCr)
Calculate permutations (nPr) and combinations (nCr) for any n and r. Shows step-by-step formula and factorial working.
Frequently Asked Questions
- What is the difference between permutation and combination?
- Permutation (nPr) counts arrangements where order matters. Combination (nCr) counts selections where order does not matter. For example, choosing a committee uses combinations; arranging letters uses permutations.
- What is the formula for permutation?
- nPr = n! / (n-r)! where n is total items and r is items chosen. For example, 5P3 = 5! / 2! = 60.
- What is the formula for combination?
- nCr = n! / (r! × (n-r)!) For example, 5C3 = 5! / (3! × 2!) = 10.