Border between horizontal and vertical dominoes
Source: Kvant Magazine No. 9 2019 M2576
March 14, 2023
combinatoricsdominoesKvant
Problem Statement
A board is divided in dominoes (rectangles with dimensions or ). [*] Prove that the total length of the border between horizontal and vertical dominoes is at most .
[*] Determine the maximum possible total length of the border between horizontal and vertical dominoes.
Proposed by B. Frenkin, A. Zaslavsky, E. Arzhantseva