Mr. Excel Seating Chart Challenge: 100 people 10 tables 11 Sessions * Can everyone meet everyone?

Mr. Excel, Bill Jelen, contacted me with a question that he’d been asked:
Can you arrange seating such that every person in attendance will sit at a table with every other person, at least once? The parameters:

– 100 people
– 10 tables
– 10 seats t each table
– 11 rounds

Bill concluded that there’s no way to connect everyone in only 11 rounds. He said the best he could achieve is 65%. Here is his video: https://youtu.be/0StppWCBgnY

I found this fascinating because it presents a real world scenarios where the ultimate goal can’t be achieved. We have to go back to the person who made the request and tell the truth. Then we have to ask if there’s any flexibility. Can we get more tables, bigger tables or add more rounds to the 11?

I came up with a solution that requires 19 rounds.

After thinking about my days as a wrestler, and round-robin tournaments, I could see adding people to 5-person teams, and then create an agenda that gets each of the 20 teams to meet, rather than try to work with 100 people.

In a real scenario, my 19 rounds would be a suggestion. The boss/client/friend/co-worker who made the request would have to decide if it’s an acceptable solution, or not.

For a list of my Excel courses at Lynda/LinkedIn:
https://www.linkedin.com/learning/instructors/oz-du-soleil
There are courses on Power Query, Good spreadsheet habits, and a weekly Excel challenge that comes out every Friday.

Website: https://ozdusoleil.com

My book: Guerrilla Data Analysis 2nd Edition

My old blog: http://datascopic.net/blog-2-2