Question 1190636
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I'll assume that order matters. If your teacher insists order doesn't matter, then ignore this current section and skip to the next section below.


If order matters, then we have 8*7*6*5 = 1680 different permutations for the algebra books. 
I started with 8 and counted down by 1 each time, multiplying along the way. I stopped once I had 4 slots filled.


We then have 5 choices for the stats book chosen, so overall there are 1680*5 = 8400 different ways to arrange the books if order matters for the algebra books.


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If order doesn't matter, then we divide that 1680 by 4! = 4*3*2*1 = 24 to get 1680/24 = 70


We divided by 24 because there are 24 ways to arrange any set of four items. 
Something like {A,B,C,D} is the same as {B,A,C,D}.


We have 70 different combinations of picking 4 books from a pool of 8 total.


There are 70*5 = 350 ways to arrange the books if order doesn't matter for the algebra books.
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