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.

(In reply to Possible Solution by broll)

Looks like there's at least one other possible solution, which differs only slightly from broll's:

1W-1W-1W-1B
2B-1B-3W-1B
1B-4W-1B-2W
2W-1B-2B-1W

In this case, the series of two squares emanating from either side of the top-right 1B are simply swapped. Are these the only two possible solutions?

Posted by Jyqm on 2010-11-30 15:24:54