🎯 Permutation & Combination Calculator
Calculate permutations (nPr) and combinations (nCr). Understand when to use each for counting problems.
Formulas & Explanation
Permutation Formula (nPr)
nPr = n! / (n-r)!
Use when order matters (e.g., arranging people in a line, creating PIN codes).
Combination Formula (nCr)
nCr = n! / (r!(n-r)!)
Use when order doesn't matter (e.g., selecting a team, choosing lottery numbers).
Examples
| Permutation | How many ways to arrange 3 books from 5? 5P3 = 60 |
| Combination | How many ways to choose 3 books from 5? 5C3 = 10 |