6

Part of 1995 Mexico National Olympiad

Problems(1)

arrangements of 0 and 1 on each square of a 4 x 4 board

Source: Mexican Mathematical Olympiad 1995 OMM P6

1

0

is placed on each square of a

4 \times 4

board. One is allowed to change each symbol in a row, or change each symbol in a column, or change each symbol in a diagonal (there are

14

diagonals of lengths

1

4

). For which arrangements can one make changes which end up with all

0

boardcombinatorics