Today i will introduce colouring proofs. For this i will give the classic example.
Problem:
Let a chessboard be given. The two black corners are cut off. Is it possible to completely cover the board with domino bricks.
Sollution:
No. A domino brick on the board always covers one black and one white tile. Since there are more white tiles than black tiles, it is impossible to completely cover the board with dominoes.
jr. math-club 