Ordering 29 CD's; how many ways?

In a library you find 12 Classical CD's, 10 Pop CD's and 7 Jazz CD's.

Question: In how many ways can you order those 29 CD's if the Classical CD's as well as the Pop CD's have to be next to each other?

How should I tackle this problem?

The answer should be: 6.3 * 10 ^ 20

Re: Ordering 29 CD's; how many ways?

Quote:

Originally Posted by

**timmeh** In a library you find 12 Classical CD's, 10 Pop CD's and 7 Jazz CD's.

Question: In how many ways can you order those 29 CD's if the Classical CD's as well as the Pop CD's have to be next to each other?

How should I tackle this problem? The answer should be: 6.3 * 10 ^ 20

I can see no reading of this question that would give that answer.

I get Can you see how?

Re: Ordering 29 CD's; how many ways?

Re: Ordering 29 CD's; how many ways?

Thanks Soroban, that makes it clear!