MathDB
a chessboard with 32 dominos

Source: 2001 Swedish Mathematical Competition p6

March 21, 2021
combinatoricscombinatorial geometryChessboarddominos

Problem Statement

A chessboard is covered with 3232 dominos. Each domino covers two adjacent squares. Show that the number of horizontal dominos with a white square on the left equals the number with a white square on the right.