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The Lightbulb Riddle...?
Ok, i heard this one recently and thought it was pretty good. Preferably some good attempts at answers please!! :)
You are standing outside the door to a single room. There is a single working light in the room and there are 3 lightswitches outside.
You are tasked with finding out which of the 3 lightswitches outside the room controls the light inside it.
The door is shut, you cannot see anything through any cracks or anything else so the only way to determine the light is on is to enter the room, but you can only go in once and cannot come back out again to try another switch.
How do you determine which switch controls the light? Xx
Close LOL, but since there is only 1 lightbulb and you turn two switches on and then one off and enter the room, you still dont know which of the two lightswitches made it hot in the first place as the light will either be on, off, hot or cold, all youve done is reduce the options from 3 lightswitches to 2 and since you can't go back out and try again then you failed. sorry! :)
3 Answers
- 9 years agoFavorite Answer
Turn the second switch on for a long time. Then turn it off and turn the 3rd switch on and go in. If the light is on, then the 3rd switch controls the light. If the light bulb is off but is hot, the second switch controls the light. Finally, if the light bulb is cold and off, then the first switch controls the light bulb.
- 9 years ago
Easily enough, just turn two of the light switches on. Wait a while, and then turn one of them off, then quickly enter the room. One light will be on, one off, and one off but still hot.
- 9 years ago
Look at the light switches, which ever looks different is the correct switch.
Source(s): experience
