Friday

August 22, 2014

August 22, 2014

Posted by **Shreya** on Friday, January 18, 2013 at 1:30am.

need help with 2 questions

1. emma is arranging her books in piles on her desk. she has 5 math books, 3 english books, and 4 science books. how many ways can she arrange them if she wants to keep the subject areas 2gether?

I did 12!/4!3!5!, but thats wrong, it should be 360 :|

2. gordon has some spare change on his desk, he got a nickel, penny and quarter. assumin that he uses at least 1 coin, how many diff sums r possible?

^ i did 3P1 * 3P1 * 3P1, but the answer is supposed to be 12 :|

- Pre Calculus 12 -
**Steve**, Friday, January 18, 2013 at 4:34amThere are 3! ways to arrange the subjects

For each such arrangement, there are 5! * 3! * 4! ways to arrange the books.

That would be 3!3!4!5! = 103680

No idea how 360 is the answer.

-------------------------------

C(3,1)+C(3,2)+C(3,3) = 3+3+1

No idea how 12 is the answer. The coins can be picked in the following ways:

p,n,q, pn,pq,nq, pnq

The order does not matter.

**Related Questions**

Permutations - 1. 4! a.) 3 b.) 6 c.) 12 d.) 24****** 2. 5! a.) 25******** b.) ...

Pre-Algebra [Combinations] - Need help with these- 1.How many groups of 4 ...

Probability (Pre-Calculus) - A class is given a list of eight study problems ...

Math: Permutations and Combinations - Need a verification: Combinations of n ...

pre calc - A math teacher uses four algebra books, two geometry books, and three...

Statistics - A raffle is being conducted with 50 tickets to be sold - one per ...

Pre-Algebra Math - Emma bought 6 new books for her collection. This increased ...

Finite Math - Please help with this problem. In a student writing contest with ...

Math - Find the probability that if the letters of the word "parallel" are ...

Maths - These questions are about permutations and combination: Find the number ...