|In one room of a house are three separate switches that are connected in some order to three light bulbs in a second room. Is it possible to visit each room once and only once and determine which switches control which lights? (You may not use a screwdriver or unscrew light bulbs to gather clues).
Total Votes: 5320
ANSWER: Yes. In the room with the switches you turn the first 2 ON and leave the 3rd switch OFF. After a couple of minutes, you turn the 2nd switch OFF. You immediately go to the room with the light bulbs. Whichever bulb is still on is connected to switch 1. You then touch the 2 bulbs that are off. Whichever bulb is still warm is connected to switch 2, and the cold bulb is connected to switch 3.