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 Duane, a parent: We have a golf outing coming up with 25 golfers playing 5 rounds in 5-somes. Is there a formula to figure out where everyone can play with different people each round? Thanks, Duane

Duane,

It is possible, though for each person to play with every other person there would have to be 6 lines.

To find the fivesomes, start with number 1, 2, ..., 25 in a 5x5 grid:

 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

Day 1: the rows
Day 2: the columns
Day 3: one from each row advancing one position each time (and wrapping around): 1, 7, 13, 19, 25; 2, 8, 14, 20, 21; etc
Day 4: one from each row advancing two positions each time (and wrapping around): 1, 8, 15, 17, 24; etc
Day 5: one from each row advancing three positions each time (and wrapping around): 1, 9, 12, 20, 23; etc

As you might expect, if there were a sixth day, you'd get the fivesomes by advancing 4 positions each time.

I hope this makes sense.
Victoria

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