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Okay, I am developing a form of music composition based on Serialism. It is geared toward MIDI and electronic musicians. I have become stuck in an extremely stoopid and frustrating place.

I am pretty sure the answer to problem 1 is 72.
12x12=144, to avoid duplicates divide by 2 = 72
Since I'm not positive about the answer to problem one that leaves me screwed on problem two. Didn't I learn this stuff in the 3rd grade or something? Why don't I remember this stuff....!? ::)


Here it is:

Serialism

Problem 1:
I am looking for the total possible combinations of 12 notes in a 12 note pattern.

Ex.:

1-2-3-4-5-6-7-8-9-10-11-12

How many ways can these numbers can be reordered without repeating them?

Problem 2:
Part 1--
I am looking for the total possible combinations of two digits from a base of 12 digits.

Ex.:

1-2
3-4
5-6
1-3
etc.

Part 2?
The same as above but with three digits.

1-2-3
3-5-7
1-6-12
etc.

I am not only looking for the solution to this problem but, how it is solved.

THANKS!
-junc

12 x 11 x ... x 1 (or a shorter notation = 12! )
On the first spot you have 12 different choises (12), on the 2nd spot you have only 11 choises left (x11), 3rd spot, 10 choises (x10), ...




(12 choises possible, 12 choises possible)
12 x 12 = 144




(12 choises possible, 12 choises possible, 12 choises possible)
12 x 12 x 12

THANK YOU! ;D