Another Logic Puzzle
Dec. 21st, 2006 08:42 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
tanithryudoSuppose you have two rooms. In room A are three light switches. In room B are three typical desk lamps. Each light switch in room A turns on/off a different lamp in room B. The light switches can only be pulled to render a light on or off; there is no mid-way dimming function. The rooms are completely separate from and opaque between each other. And finally, there is no geographic correlation between the arrangement of switches in room A and the lamps in room B.
You start off in room A, where all the switches are pointing to off. You can do whatever you want to any of the switches. After you are done, you are allowed to go to room B where you can see the results of whatever you did. You are not allowed to go back to room A and fiddle with more switches after going into room B.
The question for this puzzle is: Which light switch toggles which lamp?
Highlight to read answer:
First turn one of the lights on. Leave it on for about an hour or so. Then turn it off and turn on one of the other lights.
Go to room B. The light that is on is obviously the second switch you toggled. Feel the remaining two lights, and the one that you first switched on should be the bulb that is still warm.
Incidentally, my original answer to this was: Turn one light on and wait a couple of years for the bulb to eventually burn out. Then turn on a second light and go to room B. The burnt out bulb is obviously the first light and the one that's on is the second one. Technically the answer works. it's just less... well, functional, than the real answer.
You start off in room A, where all the switches are pointing to off. You can do whatever you want to any of the switches. After you are done, you are allowed to go to room B where you can see the results of whatever you did. You are not allowed to go back to room A and fiddle with more switches after going into room B.
The question for this puzzle is: Which light switch toggles which lamp?
Highlight to read answer:
First turn one of the lights on. Leave it on for about an hour or so. Then turn it off and turn on one of the other lights.
Go to room B. The light that is on is obviously the second switch you toggled. Feel the remaining two lights, and the one that you first switched on should be the bulb that is still warm.
Incidentally, my original answer to this was: Turn one light on and wait a couple of years for the bulb to eventually burn out. Then turn on a second light and go to room B. The burnt out bulb is obviously the first light and the one that's on is the second one. Technically the answer works. it's just less... well, functional, than the real answer.
