Round tables on graph theory
Source: Tuymaada 2005, day 1, problem 3
July 13, 2005
graph theorycombinatorics proposedcombinatorics
Problem Statement
The organizers of a mathematical congress found that if they accomodate any participant in a room the rest can be accomodated in double rooms so that 2 persons living in each room know each other. Prove that every participant can organize a round table on graph theory for himself and an even number of other people so that each participant of the round table knows both his neigbours.Proposed by S. Berlov, S. Ivanov