So logical
Joe has 16 small square cards, eight black and eight white. On each card is one of the numbers 1 2 3 or 4. There is a 1 on four white cards (W1), a 1 on six black cards (B1), a 2 on two white cards (W2), a 2 on two black cards (B2), a 3 on one white card (W3) and a 4 on one white card (W4). All Penny has to do is place the cards on the grid (above right) with a 1 on a black card in the top right corner, so that the…
