Question 617429
in how many ways can 10 different books be arranged on a shelf if there is room for 
A: all 10 Books?
Ans: 10! = 3628800 ways
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B. for only 7 Books?
Ans: 10P7 = 10!/(10-7)! = 10!/3! = 604800
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Cheers,
Stan H.
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