Three Lightbulbs.

14. Three Lightbulbs.

You are standing outside a basement door, Down the stairs, there are 3 light bulbs.

Next to you, are 3 switches. You cannot see the lights from upstairs, and you must decide which switch controls which lightbulb by going downstairs once.

How do you do this?

Submitted by Sxc Shadow · Added 30 April 2008

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Solution:

Turn on the first switch and leave it on for about 10 minutes. Then, turn it off and turn on the second switch. Go downstairs. The bulb that is on corresponds to the second switch, the bulb that is off but warm corresponds to the first switch, and the bulb that is off and cool corresponds to the third switch.

Comments (1)

skintc ★ Solved 30 June 2008

Turn on first switch, leave it on for a few minutes. Then turn it off and flip second switch.

When you go into the basement, the first switch is the bulb that is off, but hot. The second switch is the bulb that's on. The thrid switch is the bulb that's cold and off.

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