Four Colours
Write the numbers from 1 to 4 on four sets of different coloured chips. Make a 4 by 4 board and colour it, using the pattern above, with the same colours as the chips.
Put the chips on the board so that each row and column contains all four numbers. You have to put each chip on a square of the same colour. The first four chips have to be placed as shown.
Put the chips on the board so that each row and column contains all four numbers. You have to put each chip on a square of the same colour. The first four chips have to be placed as shown.