Yahoo Answers is shutting down on May 4th, 2021 (Eastern Time) and beginning April 20th, 2021 (Eastern Time) the Yahoo Answers website will be in read-only mode. There will be no changes to other Yahoo properties or services, or your Yahoo account. You can find more information about the Yahoo Answers shutdown and how to download your data on this help page.
Trending News
Logic problem?
There are two rooms connected by one door. In Room 1, there are three light switches. In Room 2 there are three light bulbs. The problem: to figure out which switch goes to which bulb.
The catch: when you open the door, all the power is disconnected and the bulbs go out. How do you figure out which switch goes to which bulb? They are incandecent bulbs.
You cannot enter the room with the light bulbs and close the door, you may only go in with door left open.
[It personally took me two weeks to figure this out and when I did it was definitely a "Doh!!!" moment.]
Well, Charisma got it. I didn't figure it out until I had to change a bulb over my desk that had burned out.
You'll get best answer as soon as I can select it.
And, yes, I STILL feel stupid for not being able to give an answer for the question.
14 Answers
- CharismaLv 61 decade agoFavorite Answer
flick one of the bulbs on , leave it for a min (like 5 Min's) then go into the other room and feel the light bulbs. Or have someone stand in the other room. or you Can take out 2 of the bulbs flick the switches and when light comes out under the door you ll know
That's the best i got
- 1 decade ago
All the power is disconnected. Of course the bulbs went out. You can tell which light (in room 2) goes to which switch (again in room 2) by the source (lamp) the bulb is attached to! THE PROBLEM NEVER STATED THAT THE SWITCHES IN ROOM 1 GO TO THE LIGHTS IN ROOM 2. Therefore, the solution I have provided is the only logical solution. All other solutions are based on assumption.
- 1 decade ago
You unscrew the bulbs? Two at a time and then go into the other room and try each switch when you see the light under the door turn on you'll know which switch belongs to the bulb. And so on.
Or you can check which bulb is warm.
- 1 decade ago
Two ways...
Flip on one switch, open the door (which turns off the power) and go in room 2 and close the door (which should return the power), thus showing you which light.
Answer 2... Flip on one switch and leave it on for over 1,000 hours. Eventually the incandescent bulb filament will burn out, leaving bits in the bulb, you can then lightly shake each bulb in the dark and hear which bulb burned out.
Thanks!
- How do you think about the answers? You can sign in to vote the answer.
- 1 decade ago
Turn one switch on and leave it on for 5 or so minutes. Go tot he room and feel for the warm bulb. Repeat for the second switch. Of course, the remaining bulb corresponds to the third one.
- Anonymous1 decade ago
switch one light switch and leave on for 6 minutes then go into other room and touch each light bulb the one that is hot it goes with it.
- Anonymous1 decade ago
take off 2 of the bulbs and the one that shines w/ the switch that you use is the one that goes w/ it. And like wise w/ the other bulbs.
- 1 decade ago
turn one switch on and wait for a little while. then open the door. the bulb that is still hot is the one that was on and connected to the switch that you turned on. repeat for each switch
- harmonyLv 41 decade ago
flick the switch one by one. the bulb that lights correspondes to that switch. u can tell if ur right cuz u will see the light from underneath the door
- 1 decade ago
You turn and leave one on for a min or so and when you enter the other room feel which one is warm; do the same for the others =]
