Factorials approximation problem

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karnten07
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Homework Statement


How is,

[(N+Q)!Q!]/[(Q+1)!(N+Q-1)!] equal to (N+Q)/(Q+1) when N,Q>>1 ??

It looks like the Q!/(N+Q-1)! cancels but i don't see how, I am going from my lecturers notes here.

Homework Equations





The Attempt at a Solution

 
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Break it up - look at the fraction as

[tex]\frac{Q!}{(Q+1)!} \cdot \frac{(N+Q)!}{(N+Q-1)!}[/tex]

For the first fraction, ask yourself "what number you would multiply [itex]Q![/itex] by to get [itex](Q+1)![/itex]"?

Do a similar analysis for the second fraction.