The 3 mystery light switches

Answer: Since you cannot see which light switch goes to any of the rooms upstairs,.. turn on one of the lights switches and leave it on for about 3 or 4 minutes. Turn that light switch back off. Turn on one of the two remaining switches and immediately go upstairs. You will now be able to figure out which switch goes to which room. Obviously the switch that you turned on before you came upstairs is the one that's on. Then go into either of the two remaining rooms and feel the light bulb. The room that has the warm light bulb is the room you turned on for 3 or 4 minutes.