MathDB
Childs in cells

Source: St Petersburg Olympiad 2014, Grade 11, P6

October 24, 2017
combinatorics

Problem Statement

In the n×nn \times n table in every cell there is one child. Every child looks in neigbour cell. So every child sees ear or back of the head of neighbour. What is minimal number children, that see ear ?
Back to ProblemsView on AoPS