unique groups of 3 from 9 groups

[HilRin]

Hi!

I need to see how many unique groups of 3 I can get out of 9 groups of 3. There can be no overlap. Each group of 3 cannot have been paired with any of the others. So far I can only come up with 4 groups. Am I missing anything? Here is what I have so far. Thank you for any help!


1A 1B 1C
2A 2B 2C = 1 grouping
3A 3B 3C


1A 2A 3A
1B 2B 3B = 2nd grouping
1C 2C 3C


1A 2A 3A
2B 3B 1B = 3rd grouping
3C 1C 2C


1A 2A 3A
3B 1B 2B = 4th grouping
2C 3C 1C

 

[HilRin]

Hi Denis,

I'm sorry I have no idea what you are talking about.

 

[pka]

how many unique groups of 3 I can get out of 9 groups of 3. There can be no overlap. Each group of 3 cannot have been paired with any of the others.

Hi Denis,
I'm sorry I have no idea what you are talking about.

That is exactly the way I felt when I first read your post.
Nine groups of three of three means there are twenty-seven individuals.
Nothing that you posted makes any sense. If you cannot post a clear question, no one can help you.

Try to clear-up your language.

 

[HilRin]

OK. I'll try and make it clearer. Sorry.

 

[Ishuda]

OK. I'll try and make it clearer. Sorry.

What I get out of it is you have 27 'items' and you want to build groups of three (obviously 9 groups of three items). Once an individual item (example, item 1) has occurred in a particular group of three with another item (same example, item 2) they can no longer appear in a group of three together (same example, item 1 and 2 can no longer appear in the same group of three together). How many such groups of [9 groups of three items] can be built?

Is that correct?