SOLUTION: I have a group of 8 people who play bridge every month. There are 4 people per table so 2 tables per month I need to develop a list of who plays with each other. I want to arrang

Algebra ->  Permutations -> SOLUTION: I have a group of 8 people who play bridge every month. There are 4 people per table so 2 tables per month I need to develop a list of who plays with each other. I want to arrang      Log On


   



Question 654404: I have a group of 8 people who play bridge every month. There are 4 people per table so 2 tables per month
I need to develop a list of who plays with each other. I want to arrange it so that everybody gets to play with each other as equal as possible over the course of a year
I feel that there has to be a simple mathmatical way of doing this instead of just trying to be random.
Thanks for your help!
Ann
AnnMarion123@hotmail.com

Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
 
Hi,
Re TY, Set UP should not result in any duplicate pairs. See below:
"arrange it so that everybody gets to play with each other as equal as possible over the course of a year"
first: number people 1-8 and Make a List of Your 28 Possible Pairings:
1 with 2-8 7 pairings
2 with 3-8 6 pairings
3 with 4-8 5 pairings
4 with 5-8 4 pairings
5 with 6-8 3 pairings
6 with 7&8 2 pairings
7 with 8 1 pairings
28 Possible pairings (Statisticallly, that would be 8C2)
1-2 1-3 1-4 1-5 1-6 1-7 1-8
2-3 2-4 2-5 2-6 2-8 2-7
3-4 3-5 3-6 3-7 3-8
4-5 4-6 4-7 4-8
5-6 5-7 5-8
6-7 6-8
7-8
As random drawing may result in 2 "1s", as You pointed out, rather than redrawing...
might be simpler to just go down the columns and choose the pairings, for ex: (1-2, 3-4) (2-3,4-5) etc
Might then recommend drawing 4 pairings(out of a box originally containing the 28)each month
(do not replace them in that box) and assign them to one of the two tables.
After 7 months, All of the 28 pairings could go back in a box for another round of drawings.