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Posted 14 March 2008 - 09:50 PM
Posted 16 March 2008 - 04:01 AM
Posted 16 March 2008 - 10:34 PM
Bulbs - Back to the Logic Puzzles
This is one of my favorite logic puzzles (Edit: it is more a practical than a logic puzzle).
Imagine you are in a room with 3 switches. In an adjacent room there are 3 bulbs (Edit: let's say in lamps which are on a regular table) - all are off at the moment, each switch belongs to one bulb. It is impossible to see from one room to another. How can you find out which switch belongs to which bulb, if you may enter the room with the bulbs only once?
Edit: No help from anybody else is allowed.
Edit: Find out which switch belongs to which bulb - identify all 3 switches (so find out what bulbs are switches 1, 2 and 3 connected to)Spoiler for Solution
O.K. Either there is something missing to this puzzle or that has got to be the dumbest thing I have ever heard. You have turned on one bulb and left it on for a few moments so it can get warm, then you shut it off and turned on another one to get it just a little warm. At this point there is no reason to enter the room since simple process of elimination allows you to designate the third switch to the only bulb not turned on.
Posted 19 March 2008 - 09:14 PM
Posted 20 March 2008 - 02:30 AM
Posted 20 March 2008 - 04:17 AM
Wait 5 minutes
Turn off switch # 1
Wait 5 minutes
Turn off switch #2 and go into the room.
Burning bulb is switch #3
Very warm unlit bulb is #2
Cooler unlit bulb is #1
Posted 21 March 2008 - 06:12 PM
Posted 22 March 2008 - 02:24 AM
Posted 23 March 2008 - 08:20 PM
Step 1) enter room
Step 2) set up mirrors
Step 3) use mirrors to determine
1) enter room
2) set cameras.
3)watch and learn
Posted 24 March 2008 - 03:58 PM
That said, I'm not sure what to do if you are in an environmentally-friendly puzzle that uses compact flourescents instead of traditional, wasteful incandescent bulbs. The CF bulbs may not be as reliable in this solution. The don't burn as hot, don't waste as much energy, and don't really respond well to suggestions of leaving a switch in the "halfway" position. I wonder if there is such a solution to a cool, energy-efficient bulb puzzle.
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