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        riddles >> medium >> Captured by Aliens
        
(Message started by: JeffBot on Nov 20^th, 2002, 10:25pm)

Title: Captured by Aliens
Post by JeffBot on Nov 20^th, 2002, 10:25pm

Heard this from a friend:

You and 49 other people are taken captive by a group of aliens. In an isolated room, the aliens have a globe that changes into three distinct colors. The aliens will bring people into the room and let them change the color of the globe if they wish. They tell you that if you can say for certain when everyone has seen the globe, they will let you all go. You are given a few moments to discuss strategy before being taken to 50 isolated cells (you know the colors of the globe).

Assuming that aliens can choose people to see the globe as many times or as few times as they want (one person may see the globe 100 times before anyone else sees it, etc.) Also, assume that there is no time limit to this game. How can you rescue yourself and the 49 other captives?

Title: Re: New Puzzle: Captured by Aliens
Post by towr on Nov 21^st, 2002, 12:03am

sounds like a variant of prisoners and a lightbulb..

So designate one person as the counter, and everyone else can change the color of the globe from the first color to the second color, and second to third the first time the globe isn't the third color. The counter will reset the globe to the first color and count..