Tiling rectangular rooms with 2×2 and 4×1.
Source: Bundeswettbewerb Mathematik 1973, round 2, problem 3
May 1, 2007
modular arithmeticcombinatorics proposedcombinatorics
Problem Statement
For covering the floor of a rectangular room rectangular tiles of sizes and were used. Show that it's not possible to cover the floor if there is one plate less of one type and one more of the other type.