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Discrete-Math · Counting

13 choose 4

13,\ 4

Step by step

  1. \binom{13}{4} = \frac{13!}{4!\,(13-4)!}

    Unordered selections: n! / (k! (n−k)!).

  2. = \frac{6227020800}{24 \times 362880} = 715

Reveal the answer
\binom{13}{4} = 715