MathDB
sum of numbers in cells numberes 2^k, inside 600x600 sqaure, 4 types of tiles

Source: 2020 Ukraine TST 1.1

January 7, 2021
combinatoricsTiling

Problem Statement

Square 600×600600\times 600 is divided into figures of four types, shown in figure. In the figures of the two types, shown on the left, in painted black, the cells recorded number 2k2^k, where kk is the number of the column, where is this cell (columns numbered from left to right by numbers from 11 to 600600). Prove that the sum of all recorded numbers are divisible by 99. https://cdn.artofproblemsolving.com/attachments/2/5/811a0d1a6bea0e15a3271f62f35b9f4848a172.png