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Problem I could not solved.

(n-3)(n-4)!/(n-5)(n-6)!=?

Note by Mehdi Balti
1 year, 6 months ago

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Comment deleted Jul 20, 2015

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@Arpan Sarangi Can you explain it :) Mehdi Balti · 1 year, 6 months ago

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@Mehdi Balti, could you please clarify what the problem is? Thanks. Victor Loh · 1 year, 6 months ago

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It's factorial and the answer will be in positive integer.Not in decimal (n-3)(n-4)!/(n-5)(n-6)!=? Mehdi Balti · 1 year, 6 months ago

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@Mehdi Balti Based on how you've clarified the problem, I'm assuming you wish to find the value of

\[x = \frac{(n-4)!(n-3)}{(n-6)!(n-5)},\]

where \(x\) is a positive integer.


Note that

\[\begin{align} x &= \frac{(n-4)!(n-3)}{(n-6)!(n-5)} \nonumber \\ &= \frac{(n-3)[(n-4)(n-5)(n-6)\cdots(3)(2)(1)]}{(n-5)[(n-6)(n-7)(n-8)\cdots(3)(2)(1)]} \nonumber \\ &= \frac{(n-3)(n-4)(n-5)!}{(n-5)!} \nonumber \\ &= (n-3)(n-4) \nonumber \end{align}\]

This value is different for different values of \(n\). I'm not sure if this is what you want, although \((n-3)(n-4)\) is clearly a positive integer for positive integer values of \(n\). Please clarify further. Thanks! Victor Loh · 1 year, 6 months ago

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@Victor Loh Yes n value is positive integer.Really thanks @Victor Loh I got it completely Now :) Thumps up for u Cheers :) Mehdi Balti · 1 year, 6 months ago

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@Victor Loh If I would not given the value but say that it's positive integer then how would you solve this ?Answer should be in positive integer. Mehdi Balti · 1 year, 6 months ago

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