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Homework Help: Simplyfing this factorial

  1. Dec 9, 2008 #1
    1. The problem statement, all variables and given/known data
    [tex] \frac{(kn)!}{(kn+k)!} [/tex]

    I was thinking:

    (kn)! = 1*2*3......(kn)
    (kn+k)! = 1*2*3......(kn)(kn+k)

    and I would be left with 1/kn+k

    But my book has the answer as:
    [tex] \frac{1}{(kn+k)(kn+k-1)....(kn+1)} [/tex]

    How can I arrive to that?
  2. jcsd
  3. Dec 9, 2008 #2
    There are k numbers between kn and kn + k, not just one.
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