Permutation & Combination Calculator
Calculate P&C problems
Permutations are arrangements where order matters. Formula: P(n,r) = n! / (n-r)!
Combinations are selections where order doesn't matter. Formula: C(n,r) = n! / (r!(n-r)!)
Factorial of n (n!) is the product of all positive integers from 1 to n. Example: 5! = 5×4×3×2×1 = 120
Quick Reference
Key Differences
- Permutations: Order matters (ABC ≠ BAC)
- Combinations: Order doesn't matter (ABC = BAC)
- Example: Choosing team captain vs. choosing team members
Common Factorials
- 0! = 1
- 3! = 6
- 5! = 120
- 10! = 3,628,800