TOT 167 1988 Spring Train J4 numbers 1 to 64 in a chessboard
Source:
May 9, 2020
combinatoricsChessboardSum
Problem Statement
The numbers from to are written on the squares of a chessboard (from to from left to right on the first row , from to from left to right on the second row , and so on). Pluses are written before some of the numbers, and minuses are written before the remaining numbers in such a way that there are pluses and minuses in each row and in each column . Prove that the sum of the written numbers is equal to zero.