Statement: There is one bulb in a room with its door closed. There are 3 switches (A,B,C) outside. You can open the door only once. You have to figure out which switch belongs to the bulb.
Solution:
1) Turn on the first switch and keep it on for a few minutes.
2) Switch off the first switch and turn on second switch.
3) Immediately enter the room
a) If bulb is on, second switch it is.
b) If bulb is off and warm, then first switch.
c) If bulb is off and cold, then third switch.
Solution:
1) Turn on the first switch and keep it on for a few minutes.
2) Switch off the first switch and turn on second switch.
3) Immediately enter the room
a) If bulb is on, second switch it is.
b) If bulb is off and warm, then first switch.
c) If bulb is off and cold, then third switch.
