Planos

Calculadora de permutação e combinação

Digite n (itens para escolher) e r (itens escolhidos).

Resultado

Digite os valores e toque em Calcular para ver o resultado.

Fórmula

nPr=n!(n−r)!{}_nP_r = \frac{n!}{(n - r)!}

Permutations: order matters.

nCr=n!r! (n−r)!{}_nC_r = \frac{n!}{r!\,(n - r)!}

Combinations: order does not matter.

Como usar esta calculadora

  1. Enter whole numbers with r no bigger than n.
  2. Press Calculate to get both counts.

Exemplo resolvido

Choose 2 from 5

5P2 = 5 × 4 = 20 ordered arrangements.

5C2 = 20 / 2! = 10 unordered selections.

Perguntas frequentes

When does order matter?

For rankings or codes (permutations). For teams or hands of cards, order doesn’t matter (combinations).

Are the answers exact?

Yes — even very large counts are computed exactly.

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