MathDB
2-colorable way for numbers

Source: Vietnam TST 2023, P6

April 14, 2023
combinatorics

Problem Statement

Let n3n \ge 3 be an integer and SS be a set of nn elements. Determine the largest integer knk_n such that: for each selection of knk_n 33-subsets of SS, there exists a way to color elements of SS with two colors such that none of the chosen 33-subset is monochromatic.