Cutting the chessboard
Source: 2014 Czech & Slovak Mathematical Olympiad, Rnd. III, Cat. A
May 20, 2014
combinatorics unsolvedcombinatorics
Problem Statement
Suppose we have a chessboard. Each edge have a number, corresponding to number of possibilities of dividing this chessboard into domino pieces, such that this edge is part of this division. Find out the last digit of the sum of all these numbers.(Day 1, 3rd problem
author: Michal Rolínek)