Lightbulb
Outside a room there are three light switches. One of switch is connected to a light bulb inside the room.
Each of the three switches can be either 'ON' or 'OFF'.
You are allowed to set each switch the way you want it and then enter the room(note: you can enter the room only once)
Your task is to then determine which switch controls the bulb ??
Reply by
cordilmar
- July 05 2013 11:20:28 AM
flip the first switch. Leave it on for five minutes, and then turn it off. Then turn on the second switch and go into the room. If the lightbulb is warm but off, the first switch is the right one. If the light is on, it's the second switch. If the bulb is off and cold, it's the third switch.