There are three desk lamps standing on a desk in room A. You, however, are in room B where you cannot see the lamps. There are three light switches in room B that control the three desk lamps in room A. All light switches are in the off position. You get fifteen minutes to think and act and then you will be brought to room A, where you have to state which switch corresponds to which lamp. What do you do?

Question

lollylau · Answer

turn one on and off quickly
turn one on.
ones burned, ones on , ones off.

vishal_kothari · Answer

http://thomer.com/riddles/

lollylau · Answer

or go back to room B and check.

anonymous · Answer

But how can we be sure that one burned up, and it isn't fair to burn a bulb.

lollylau · Answer

you can SEE that its burned.

lollylau · Answer

turn one switch to the middle so it alternates its current all the time.

anonymous · Answer

No, I think it wouldn't

radar · Answer

I think LollyLau has it right.  By turning one light switch on and then back off, that light bulb will be warm to the touch, and one will be off and cool, and course the one with the switch  in the on position will be glowing.  Good logic lollylau