There are 16 cards: 8 black and 8 white. On each card is a number between 1 and 4 inclusive. There are:

4 white cards with a 1     6 black cards with a 1
2 white cards with a 2     2 black cards with a 2
1 white card with a 3 
1 white card with a 4 

Arrange the cards into a 4x4 grid such that the number on each card represents the number of black cards among its 2, 3 or 4 orthogonally adjacent cards, and so that the top-rightmost card is a black card with a 1 on it.

1W,2W,1B,1B
2B,1B,3W,1W
1B,4W,1B,1W
2W,1B,2B,1W

Posted by broll on 2010-11-30 12:56:24