Nonograms (also known as "Griddlers" or "Paint By Numbers") were invented by Non Ishida in 1987. Originally trying to design pictures that could be created by turning the lights on or off in the windows of skyscrapers, Ishida soon realized that the same principle could used as the basis for a new genre of logic puzzle. Since then, enigmatologists around the world have wasted hours solving them online and completing entire books of these elegant brainteasers.
posted by Shadowkeeper on Sep 26, 2002 - 16 comments

What Color is My Hat? I [heart] these mathematical conundrums -- simple, easy-to-state, seemingly obvious logic problems that have solutions that completely defy common sense. Here's another you can spring on a friend: "You want to fry up three pieces of french toast. You have a frying pan that is just large enough to accomodate two pieces of bread at a time. If it takes you 30 seconds to fry one side of bread, and each piece of must be fried on both sides, how long will it take you to cook up three pieces (assuming that the act of flipping a piece or adding/ removing it to or from the pan takes no time). Think about it. Answer inside.
posted by Shadowkeeper on May 25, 2001 - 24 comments