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kcla1996
You have checked out b books from the library, where b is a number greater than 5. You plan to read three of the books and return them at the end of this week. In how many ways can you pick the books you will read first, second, and third?
Hint: you have 'b' choices for the first book, b-1 choices for the second book and b-2 choices for the third book
Look up the counting principle and that may help you out
It's not counting as in (1, 2, 3, 4...), it's counting as counting a very large number of items http://www.regentsprep.org/Regents/math/ALGEBRA/APR1/Lcount.htm
close, but not quite
Say you pick out 10 books, you would have 10 books for the first choice, 9 for the second, and 8 for third So you would have 10*9*8 = 720 choices possible
multiply out b, b-1 and b-2
b(b-1)(b-2) = ???