Awesome riddle I found on Yahoo Answers (not mine): There are people trapped on an island with no mirrors or anything to see their own reflections. They have no way to communicate with eachother except they can all understand the leader who rarely speaks. 100 of them have brown eyes, 100 have blue eyes, and the leader has green eyes. In order to escape the island, a person has to figure out his own eye color (This person cannot use communication or reflection to do it) and leaves the island that night. Everyone knows everybody else's eye color but don't know their own (for all they know, there could be 99 people with brown eyes and 101 with blue). Keep in mind, they all think alike and are perfect logicians. One day, the leader says "I can see someone with brown eyes". How many people leave the island? (Hint: on what night did they leave the island?)
It's math.
The answer? Here it is: 100 brown eyed people leave on the hundredth night. Think of it logically. If there was 1 brown eyed, 1 blue eyed, and 1 green eyed with the same question, the brown eyed person would immediately leave on the first night because he knows he is the only possibility. If there was 2 brown and 2 blue, they would wait one night, and then one brown eyed guy would realize that the other one didnt leave and realize he has brown eyes because thats the only reason the other guy didnt leave. So two leave on the second night. If there was 3 and 3, they would leave on the third night. This can go on up until 100.
I just found this and I thought it was really interesting, so I posted it.
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