Problem 2 of Finals
Source: VI International Festival of Young Mathematicians Sozopol, Theme for 10-12 grade
January 11, 2020
combinatoricsset theory
Problem Statement
On the VI-th International Festival of Young Mathematicians in Sozopol teams were participating, each of which was with participants (). The organizers of the competition separated the participants into groups, each with people, in such way that no two teammates are in the same group. Prove that there can be found participants no two of which are in the same team or group.