Tuesday, March 1, 2011

Light Bulbs & Switch Puzzles

You are standing in a hallway next to three light switches, all of which are
off. Each
switch operates a different incandescent light bulb in the room at the end
of the hall.
You cannot see the lights from where the switches are. Determine which light
corresponds to each switch. You may go into the room with the lights only
once.

1 comment:

Shashank Mani said...

switch on one of the bulbs, keep it on for some time. Then switch if off and
switch on another bulb, then go into the room. One bulb would be glowing,
another one would be hot, and the last would be off and cold. Thus we can
determine the 3 switches by visiting the room just once.