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 ??
Switch the FIRST - ON
After 10 mins ... Switch the SECOND - ON
Leave the THIRD - OFF
Go to the room, check the bulb:
(1) If ON and HOT --> First Switch is Connected
(2) If ON and NOT HOT --> Second Switch is Connected
(3) If OFF --> Third Switch is Connected.