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Three bulbs riddle

democrates · 2005-09-16 16:45:02

There are three light bulbs in a room, and three light switches outside the room. You are outside, and want to match up which switch goes with which light bulb. You can only travel into the room once, and cannot come back in again. You can do anything you want upon entering the room. How can you set the situation so that…

16-09-2005 4:45pm

#1

democrates

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There are three light bulbs in a room, and three light switches outside the room. You are outside, and want to match up which switch goes with which light bulb. You can only travel into the room once, and cannot come back in again. You can do anything you want upon entering the room. How can you set the situation so that you will know which switch goes with which light bulb?

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Comments

#2 16-09-2005 5:01pm

emaherx

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assuming all lights are off
turn on one for 2 minutes, then turn it off
turn on the second one and walk in
the bulb connected to the first switch will be off but hot
the bulb connected to the second switch will be on
the bulb connected to the third will switch will be off and cold

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#3 16-09-2005 5:15pm

KieranusTyranus

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Hes Right I knew it too.

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#4 16-09-2005 5:19pm

emaherx

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KieranusTyranus wrote:

Hes Right I knew it too.

a likely storey :0)

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#5 16-09-2005 5:46pm

democrates

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Well impressed, that took me a quarter of an hour to work out when I first heard it.

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