Combinatorics Calculator
Calculate permutations P(n,r), combinations C(n,r), multinomial coefficients, and dice roll probabilities.
Complete User Guide
P(n,r) & C(n,r): enter n and r. Multinomial: enter group sizes separated by spaces. Dice Probability: enter dice count, sides, and target sum.
The Mathematical Formula
C(n,r) = n! / (r!(n-r)!)
P(n,r) = n!/(n-r)! (ordered). C(n,r) = n!/(r!(n-r)!) (unordered). Multinomial: (n1+n2+...+nk)! / (n1!×n2!×...×nk!).
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