1×2 dominoes are placed on an 8×8 chessboard without overlapping. They may partially
stick out from the chessboard but the center of each domino must be strictly inside the
chessboard (not on its border). Place on the chessboard in such a way:
a) at least 40 dominoes, (3 points)
b) at least 41 dominoes, (3 points)
c) more than 41 dominoes. (6 points)(Mikhail Evdokimov) combinatoricsgeometryChessboardRussia