SOLUTION: Bob has 7 books he wants to put his bookshelf. 1. How many possible arrangements of books are there? 2. What if bob has room on the shelf for only 3 of vthe 7 books. In how many w

Algebra ->  Permutations -> SOLUTION: Bob has 7 books he wants to put his bookshelf. 1. How many possible arrangements of books are there? 2. What if bob has room on the shelf for only 3 of vthe 7 books. In how many w      Log On


   

Question 198768: Bob has 7 books he wants to put his bookshelf. 1. How many possible arrangements of books are there?
2. What if bob has room on the shelf for only 3 of vthe 7 books. In how many ways can he arrange the books now?
Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!


7 ways to pick the first book, then 6 ways to pick the second book, and so on...

So:



For 3 of 7:



So you want:



You get to do your own arithmetic.


John