Results 1 to 4 of 4

- February 18th 2010, 02:34 AM #1

- Joined
- Dec 2008
- Posts
- 288

- February 18th 2010, 03:04 AM #2

- Joined
- Nov 2005
- From
- someplace
- Posts
- 14,972
- Thanks
- 4

- February 19th 2010, 04:33 AM #3

- Joined
- Dec 2008
- Posts
- 288

- February 20th 2010, 07:56 AM #4

- Joined
- May 2006
- From
- Lexington, MA (USA)
- Posts
- 12,026
- Thanks
- 841

Hello, hmmmm!

You got it!

How many positive integer divide such that they are not prime or 1?

There are 8 choices for the 2's: .

There are 9 choices for the 3's: .

Hence, there are: . choices for numbers of the form

But this includes: .

. . The rest are all composite.

Therefore, the answer is: .