[Guest]

There is 3 switches of an electrical bulb, but only one works for that bulb, the bulb is in another room and you can't see its light from where the switches are,

The main thing is a person can go to another room just once and he has to tell like the which switch lights the bulb

[Guest]

Switch on the first switch and leave it on for a few minutes. Then switch it off and switch on the second. Now go to the room with the bulb. If the bulb is on, the second switch is the right one. If it is off but hot, its the first switch. If its off and not hot, its the third switch

Edited September 25, 2009 by DeeGee

[rookie1ja]

Welcome to the Den, varin. This is one of my favorite puzzles. It's actually the very first among my Logic Puzzles and it's also quite often posted in this forum. Since it's already part of this site and DeeGee gave the correct solution I will close this thread.

Feel free to post puzzles that are new and remember that you can always check that via the search box - detailed help on searching is in in the Board Guidelines as well.

Enjoy the Den