Question: 3 light switches downstairs. 3 rooms upstairs. You can only go upstairs 1 time. From anywhere you go downstairs you can not see any lights on or off upstairs. How can you figure out which switch goes to which room?
Answer: *Turn on any switch and leave it on for a minute or two. Turn that switch off, turn on one of the other two switches and go upstairs. The switch that is on obviously goes to that room. Go to the other two rooms and feel the bulbs. The room with the hot or warm bulb goes to the first switch you turned on.