MathDB

Colored table

Source: St Petersburg Olympiad 2015, Grade 9, P3

October 17, 2017

combinatorics

Problem Statement

All cells of

2015 \times 2015

table colored in one of

4

colors. We count number of ways to place one tetris T-block in table. Prove that T-block has cell of all

4

colors in less than

51\%

of total number of ways.