MathDB
unrestricted supply of bricks 1 x 1 x 3, 3 cubes 1x1x1, box m x n x k

Source: Tournament of Towns, Junior O-Level , Fall 2019 p5

April 19, 2020
combinatoricsTilingtiles

Problem Statement

Basil has an unrestricted supply of straight bricks 1×1×31 \times 1 \times 3 and Γ-shape bricks made of three cubes 1×1×11\times 1\times 1. Basil filled a whole box m×n×km \times n \times k with these bricks, where m,nm, n and kk are integers greater than 11. Prove that it was sufficient to use only Γ-shape bricks.
(Mikhail Evdokimov)