SOLUTION: In how many ways can be arranged on a bookshelf eight different books in order: a) 3 of the books are always together b) 3 of the books have not been together ever sorry a

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Question 831238: In how many ways can be arranged on a bookshelf eight different books in order:
a) 3 of the books are always together
b) 3 of the books have not been together ever
sorry about my english

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
In how many ways can be arranged on a bookshelf eight different books in order:
a) 3 of the books are always together
arrangements of the 3 books: 3! = 6
treating the 3 as a units, # of arrangements = 6! = 720 ways
Ans: 6*720 = 4320 ways
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b) 3 of the books are never together
Random # of arrangements:: 8! = 40320
# with 3 chosen books never together: 40320-4320 = 36000
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Cheers,
Stan H.
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