20 finalists, 6 problems, 5 contestants vs 2 problems ?
Source: 2014 Swedish Mathematical Competition p5
May 1, 2021
combinatorics
Problem Statement
In next year's finals in Schools Mathematics competition, finalists will participate. The final exam contains six problems. Emil claims that regardless of results, there must be five contestants and two problems such that either all the five contestants solve both problems, or neither of them solve any of the two problems. Is he right?