Guides ยท Math
Permutations vs Combinations
Count arrangements
Permutations count ordered selections; combinations count unordered; use factorial-based formulas to compute counts for choices without repetition.
- nPr
- nCr
- factorial
- arrangements
- order
Define
Permutations consider order; combinations do not.
Compute
nPr = n!/(n-r)!; nCr = n!/(r!(n-r)!).
Apply
Use permutations for ordering problems; combinations for grouping.