Author |
Topic: Light Bulbs & Switches Variation (Read 14558 times) |
|
alien2
Uberpuzzler
Gender: 
Posts: 6989
|
 |
Light Bulbs & Switches Variation
« on: Aug 24th, 2013, 5:25am » |
 Quote  Modify
|
You are in a room with three light switches, each of which controls one of three light bulbs in the next room. You know which switch is initially on whereas two switches are off. Two ceiling bulbs are out of reach while one is the hanging bulb. Your task is to determine which switch controls which bulb. You can't see into one room from the other. You are allowed only one chance to enter the room with three light bulbs. How can you determine with certainty which light switch goes with which light bulb?
|
|
 IP Logged |
|
|
|
Grimbal
wu::riddles Moderator
Uberpuzzler
Gender:
Posts: 7527
|
 |
Re: Light Bulbs & Switches Variation
« Reply #1 on: Aug 26th, 2013, 7:53am » |
Quote Modify
|
I think you can't.
There is no way to make sure that the 2 bulbs out of reach are not both on or both off. If it happens, there is no way to tell them apart.
|
|
IP Logged |
|
|
|
alien2
Uberpuzzler
Gender:
Posts: 6989
|
|
Re: Light Bulbs & Switches Variation
« Reply #2 on: Aug 26th, 2013, 8:44am » |
Quote Modify
|
You can determine with certainty which switch goes with which bulb.
|
| « Last Edit: Aug 27th, 2013, 1:20pm by alien2 » |
IP Logged |
|
|
|
gotit
Uberpuzzler
Gender:
Posts: 804
|
|
Re: Light Bulbs & Switches Variation
« Reply #3 on: Aug 26th, 2013, 10:45am » |
Quote Modify
|
Are we allowed to take something with us inside the room with light bulbs?
|
|
IP Logged |
All signatures are false.
|
|
|
gotit
Uberpuzzler
Gender:
Posts: 804
|
|
Re: Light Bulbs & Switches Variation
« Reply #4 on: Aug 26th, 2013, 10:57am » |
Quote Modify
|
I was thinking about manipulating the connections i.e Switch 1 -> Switch 2, Switch 2 -> Switch 3 and Switch 3 -> Switch 1. And if the two unreachable bulbs are in the same state, I was thinking that perhaps we can tell them apart based on the temperature of the hanging bulb . But it's too late in the night too think anymore. Will resume thinking tomorrow, unless someone comes up with a solution.
|
|
IP Logged |
All signatures are false.
|
|
|
alien2
Uberpuzzler
Gender:
Posts: 6989
|
|
Re: Light Bulbs & Switches Variation
« Reply #5 on: Aug 28th, 2013, 12:56am » |
Quote Modify
|
on Aug 26th, 2013, 10:45am, gotit wrote:| Are we allowed to take something with us inside the room with light bulbs? |
|
Nope.
|
|
IP Logged |
|
|
|
rmsgrey
Uberpuzzler
    
Gender:
Posts: 2873
|
|
Re: Light Bulbs & Switches Variation
« Reply #6 on: Aug 28th, 2013, 4:36am » |
Quote Modify
|
Trace the wires?
|
|
IP Logged |
|
|
|
alien2
Uberpuzzler
Gender:
Posts: 6989
|
|
Re: Light Bulbs & Switches Variation
« Reply #7 on: Aug 28th, 2013, 5:04am » |
Quote Modify
|
Nah, man.  
|
|
IP Logged |
|
|
|
gotit
Uberpuzzler
Gender:
Posts: 804
|
|
Re: Light Bulbs & Switches Variation
« Reply #8 on: Aug 28th, 2013, 8:02am » |
Quote Modify
|
Use color to differentiate between the two out of reach bulbs.
|
|
IP Logged |
All signatures are false.
|
|
|
alien2
Uberpuzzler
Gender:
Posts: 6989
|
|
Re: Light Bulbs & Switches Variation
« Reply #9 on: Aug 28th, 2013, 8:27am » |
Quote Modify
|
All three are identical and standard light bulbs.
|
|
IP Logged |
|
|
|
gotit
Uberpuzzler
Gender:
Posts: 804
|
|
Re: Light Bulbs & Switches Variation
« Reply #10 on: Aug 28th, 2013, 8:50am » |
Quote Modify
|
If a bulb glows for too long, it might create a dark patch on the bulb or on the wall around it. May be that can help.
|
|
IP Logged |
All signatures are false.
|
|
|
alien2
Uberpuzzler
Gender:
Posts: 6989
|
|
Re: Light Bulbs & Switches Variation
« Reply #11 on: Aug 28th, 2013, 11:53am » |
Quote Modify
|
I see. You cannot be certain it will work.
|
|
IP Logged |
|
|
|
Grimbal
wu::riddles Moderator
Uberpuzzler
Gender:
Posts: 7527
|
|
Re: Light Bulbs & Switches Variation
« Reply #12 on: Aug 30th, 2013, 1:48am » |
Quote Modify
|
The light bulbs that are out of reach, can you still tell whether they are hot or not?
|
|
IP Logged |
|
|
|
alien2
Uberpuzzler
Gender:
Posts: 6989
|
|
Re: Light Bulbs & Switches Variation
« Reply #13 on: Sep 8th, 2013, 5:41am » |
Quote Modify
|
on Aug 30th, 2013, 1:48am, Grimbal wrote:| The light bulbs that are out of reach, can you still tell whether they are hot or not? |
|
You can't tell whether they are hot or cold.
The riddle is tricksy.
|
|
IP Logged |
|
|
|
Grimbal
wu::riddles Moderator
Uberpuzzler
Gender:
Posts: 7527
|
|
Re: Light Bulbs & Switches Variation
« Reply #14 on: Sep 8th, 2013, 1:36pm » |
Quote Modify
|
OK, then.
You tamper with the wires so all switches control all lamps. (each switch reverses the state).
Or you cut all wires. Now, you know which switch controls which bulb: none of them does.
|
|
IP Logged |
|
|
|
alien2
Uberpuzzler
Gender:
Posts: 6989
|
|
Re: Light Bulbs & Switches Variation
« Reply #15 on: Sep 8th, 2013, 2:03pm » |
Quote Modify
|
Your answers are not correct but still they made me laugh so I thank you. 
|
|
IP Logged |
|
|
|
swapnilraja1212
Newbie
Posts: 18
|
|
Re: Light Bulbs & Switches Variation
« Reply #16 on: Sep 17th, 2013, 12:31am » |
Quote Modify
|
Looks a bit complex question. Could you please answer it now.
|
|
IP Logged |
|
|
|
alien2
Uberpuzzler
Gender:
Posts: 6989
|
|
Re: Light Bulbs & Switches Variation
« Reply #17 on: Sep 17th, 2013, 3:25am » |
Quote Modify
|
I will say the answer if necessary, but not today. Give it time. There are no omitted objects. Just consider what is said in the riddle. You should put a certain part of the riddle under the magnifying glass though.
|
|
IP Logged |
|
|
|
gotit
Uberpuzzler
Gender:
Posts: 804
|
|
Re: Light Bulbs & Switches Variation
« Reply #18 on: Sep 17th, 2013, 6:51am » |
Quote Modify
|
on Sep 17th, 2013, 3:25am, alien2 wrote:| You should put a certain part of the riddle under the magnifying glass though. |
|
Okay. So first time you enter the room. The next time you stand outside the room and peep in.
|
|
IP Logged |
All signatures are false.
|
|
|
alien2
Uberpuzzler
Gender:
Posts: 6989
|
|
Re: Light Bulbs & Switches Variation
« Reply #19 on: Sep 22nd, 2013, 12:49am » |
Quote Modify
|
Not even close.
|
|
IP Logged |
|
|
|
Grimbal
wu::riddles Moderator
Uberpuzzler
Gender:
Posts: 7527
|
|
Re: Light Bulbs & Switches Variation
« Reply #20 on: Sep 22nd, 2013, 1:50am » |
Quote Modify
|
Do you start the riddle in the room with the light bulbs? I.e. you are there twice but you enter it only once, when you return.
Can you ask someone else to enter the room?
Do you have an RC drone?
Do you use mirrors?
Do you have any means to sense any property of the light bulbs without being inside?
Do you have such a long arm that you can play with the switches from the next room?
Is the magnifying glass important?
|
| « Last Edit: Sep 22nd, 2013, 1:52am by Grimbal » |
IP Logged |
|
|
|
Nursejim
Junior Member
The 1 Inch Punch
Gender:
Posts: 53
|
|
Re: Light Bulbs & Switches Variation
« Reply #21 on: Sep 22nd, 2013, 6:18am » |
Quote Modify
|
Maybe like the riddle says....... Each switch controls "one" light bulb so whichever one is on when you walk in is controlled by all three switches. Just a guess. These riddles are addicting! 
|
|
IP Logged |
Advanced Sales Funnel System
|
|
|
Grimbal
wu::riddles Moderator
Uberpuzzler
Gender:
Posts: 7527
|
|
Re: Light Bulbs & Switches Variation
« Reply #22 on: Sep 23rd, 2013, 3:15am » |
Quote Modify
|
Can you sense the heat of a lamp bulbs that is out of reach for example by spitting on it? Or by using infra-red goggles?
|
|
IP Logged |
|
|
|
alien2
Uberpuzzler
Gender:
Posts: 6989
|
|
Re: Light Bulbs & Switches Variation
« Reply #23 on: Sep 23rd, 2013, 7:05am » |
Quote Modify
|
on Sep 22nd, 2013, 6:18am, Nursejim wrote:| Maybe like the riddle says....... Each switch controls "one" light bulb so whichever one is on when you walk in is controlled by all three switches. |
|
Nice try!  Alas, each switch controls a different bulb. Keep thinking like that.
on Sep 22nd, 2013, 1:50am, Grimbal wrote:
Do you have any means to sense any property of the light bulbs without being inside? |
|
Only if you are a psychometrist. Just kidding. You are on the right track.
on Sep 22nd, 2013, 1:50am, Grimbal wrote:| Do you have such a long arm that you can play with the switches from the next room? |
|
LOL.
|
|
IP Logged |
|
|
|
Grimbal
wu::riddles Moderator
Uberpuzzler
Gender:
Posts: 7527
|
|
Re: Light Bulbs & Switches Variation
« Reply #24 on: Sep 23rd, 2013, 7:53am » |
Quote Modify
|
Pull on one of the wires (where the switch is off). The corresponding bulb is the one that is now touching the ceiling.
|
|
IP Logged |
|
|
|
|
RIDDLES SITE
WRITE MATH!
Home 
Help 
Search 
Members 
Login 
Register
Reply
Notify of replies
Send Topic
Print