Math theory question

I know this is not a math forum, but I am really stuck. I am using a theory of mathematics in one of my pieces, but I don't know how it is called. So, I was hoping if anyone knew how it is called. Here's how it goes:

Suppose we have three different objects, a green one, a red one and a yellow one. There are seven different combinations you can make with these three objects:

1, 2, 3) each of the three objects alone

4, 5, 6) pairs (green-red, red-yellow, green-yellow)

7)all the three objects together

Thanks!

Alexandros

I believe this is what you are describing:

Combination -- from Wolfram MathWorld

I believe this is what you are describing:

Combination -- from Wolfram MathWorld

Thanks, cygnusdei!

This is how the example I wrote would be written using math:

S = [3!/3!] + [3!/2!(3-2)!] + [3!/1!(3-1)!] = 1 + 3 + 3 = 7

:)

Permutations and combinations, I think.

Permutations and combinations

I hate the wikipedia articles on mathematics - they're all so overly complicated and so over the top, that's it's hard for someone who just wants some information on the topic to find what they want easily and nicely.

I hate the wikipedia articles on mathematics - they're all so overly complicated and so over the top, that's it's hard for someone who just wants some information on the topic to find what they want easily and nicely.

Yes, so do I, though I guess the aim of the authors and the site in general is not to write articles that are accessible to everyone, but articles that are as informative as possible (even though most of the times this is not the case)...

Alexandros

Heh. On the other hand, there is always simple wikipedia:

Permutation - Simple English Wikipedia, the free encyclopedia

I always enjoy looking up very complicated topics on simple wikipedia and see how people struggle to lay them out in simple words, such as calculus, the Calabi-Yau manifold, time, life, universe, idea, mind etc etc.. that's how I waste my free time..

just like xkcd:

Lol, I'd never noticed that there is also Simple English Wikipedia. Interesting... I guess. :unsure:

I usually waste my free time reading most insignificant articles I find on it (Wikipedia) like for example the life of the daughter of the friend of Queen's Elizabeth I second gardener (apparently she fired the first one, because he was over watering her favourite petunias and they withered... I'm joking of course).

It's amazing what you can find there...

Alexandros

P.S. I just typed three random letters and I got a result: byo

Alexandros, the exact name your looking for is "Combinatorics"

Combinatorics - Wikipedia, the free encyclopedia