Tuesday, August 29, 2006

Brain Teaser

Here is another brain teaser from I.Q. Challenge.

Three switches outside a windowless room are connected to three lightbulbs inside the room. How can you determine which switch is connected to each bulb, if you may open the door and enter the room only once?

The answer is in the comments.


Nancy said...


Flip the first switch on, wait one minute, and then flip that switch off. Then flip the second switch on and enter the room.

The bulb powered by the first switch will be off, but still warm. The bulb powered by the second switch will be on. And the bulb powered by the third switch will be off and cold.

daisy said...

Very enlightening.

Kimmy said...

I never would have thought of that!