Problem #PRU-110083

Problems Combinatorics Painting problems Methods Pigeonhole principle Pigeonhole principle (finite number of poits, lines etc.) Algebra and arithmetic Word problems Tables and tournaments Tables and tournaments (other)
 12–14  3.0

Problem

Can the cells of a \(5 \times 5\) board be painted in 4 colours so that the cells located at the intersection of any two rows and any two columns are painted in at least three colours?