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Old 08-17-2004, 04:00 PM   #1 (permalink)
ManWithAPlan
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Location: M[ass]achusetts
Riddle: The Watch

You have a very nice, shiny watch. But this is no ordinary watch. This watch can answer two yes or no questions 100% accurately per day You ask, and either a blue or yellow light will flash. Unfortunatley, you don't know which light means yes and which light means no, and you can never find out because there's a 50-50 chance of the lights switching every night.

You happen to be on a game show. The rules are simple. There are three doors. Behind two are goats. Behind one is a shiny red car. Obviously, you want the car. You can choose any door, after asking the watch two questions.

So tell me, What are two questions you can ask so that you will have a 100% chance of getting the car? Remember, it has to work EVERY TIME



-----

i don't know the answer yet, but i think i've stumbled onto something...

to solve it, it does not matter which is yes, you just have to use the answers to gain two possible scenarios, (if a then b ) (if not a then not b) or (if a then not b) (if not a then b)

i think that one of the scenarios always has to come out false so you can eliminate it (or you get two possible answers)

the first choice should not automatically eliminate either a negative or affirmative answer for the second one (are the goats together? and are the goats on the ends))


NOTE: these are just hypotheses, not absolute facts because i havn't gotten the answer yet.


finally here is a crude little chart to help us figure it out.




[O] [X] [X]
[X] [O] [X]
[X] [X] [O]
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