Question 46
The entries of an $8 \times 8$ chessboard are numbered by the numbers $1, 2, \ldots, 64$ in such a way that the sum of the four numbers in each of its parts of one of the forms
is divisible by the same integer $N$. For which of the integers $3$, $4$, $5$ is this possible?
is divisible by the same integer $N$. For which of the integers $3$, $4$, $5$ is this possible?