Question

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?

Answer 1

you use permutation i believe

Answer 2

\[nPr = \frac{n!}{(n-r)!}\]
\[\implies \frac{5!}{(5-3)!}\]

Answer 3

That's if you check out exactly 5 books, but you check out b books where b > 5

Answer 4

the choices are

A. b3 ways

B. b3- 3b2 + 2b ways

C. b3 - 9b2 + 27b - 27 ways

D. 5b - 3 ways

Answer 5

You have b choices for the first book, b-1 choices for the second, and b-2 choices for the third

Multiply out all the choices to get your answer

Answer 6

lol why cant i ever get these combinations and permutations right

Answer 7

i still dont understand??