Question 7
(FRG 5)
(a) Decide whether the fields of the $8\times8$ chessboard can be 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 four.
(b) Solve the analogous problem for
(a) Decide whether the fields of the $8\times8$ chessboard can be 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 four.
(b) Solve the analogous problem for