A mindbending logic puzzle. A thousand people on the island, 900 brown-eyed and 100 blue-eyed; anyone who learns their own eye color must kill themself the next day; a visitor mentions that there is a blue-eyed person on the island; what happens? Nothing, you say, because they already know that? Wrong. Further details at the Terry Tao post linked above, but don't scroll down below the boxed description unless you want hints and/or spoilers. [more inside]
posted by languagehat on Feb 15, 2008 - 390 comments