Page 1 of 1

Lateral Thinking III

Posted: February 16th, 2009, 1:05 pm
by Holmes
" The problem of the Three electrical switchs "

In all the problems that require lateral thinking, this is the one I like most.
First of all I want to say that there aren´t any types of "tricks". It is a problem that, with the pieces of information given, it can be resolved. Here it goes:

You have deserted room with only one lightbulb one the roof. The electrical switch that activates the light is outside the room. However, there isn´t only one electrical switch, there are three. Only one switch activates the light (The light works, obviously). The problem consists on the following: the door of the room is closed. You have all the time you want to "play" with the switchs. You can use any combination you want with them, but you can only go in the room once. At the moment you go out the room, you must be capable to say: "This is the switch that activates the light."The three switchs are in the same position: Off.
Let´s get it clearer: while the door is closed and you are outside, you can entertain yourself with the switchs as you wish. But, there will be a moment where you´ll have to decide to go in the room. There are no problems. You do it. But when you come out, you´ll have to be able to answer the question orf which of the three switchs is the one that activates the light?
One more time: the problem hasn´t got any type of tricks. It isn´t that you can see under the door or that there is a window on the door. It is a problem that can be resolved.

                                                                 Let´s see how you reason, shall we?  ;)

Re: Lateral Thinking III

Posted: February 16th, 2009, 2:02 pm
by sstimson
Holmes wrote: " The problem of the Three electrical switchs "

In all the problems that require lateral thinking, this is the one I like most.
First of all I want to say that there aren´t any types of "tricks". It is a problem that, with the pieces of information given, it can be resolved. Here it goes:

You have deserted room with only one lightbulb one the roof. The electrical switch that activates the light is outside the room. However, there isn´t only one electrical switch, there are three. Only one switch activates the light (The light works, obviously). The problem consists on the following: the door of the room is closed. You have all the time you want to "play" with the switchs. You can use any combination you want with them, but you can only go in the room once. At the moment you go out the room, you must be capable to say: "This is the switch that activates the light."The three switchs are in the same position: Off.
Let´s get it clearer: while the door is closed and you are outside, you can entertain yourself with the switchs as you wish. But, there will be a moment where you´ll have to decide to go in the room. There are no problems. You do it. But when you come out, you´ll have to be able to answer the question orf which of the three switchs is the one that activates the light?
One more time: the problem hasn´t got any type of tricks. It isn´t that you can see under the door or that there is a window on the door. It is a problem that can be resolved.

                                                                Let´s see how you reason, shall we?  ;)
Let me ask a dumb question to remove a way of doing this problem. I sure you will not allow this, but here it goes.

Open the door but do not enter the room. Wait for night. then while outside the room find the switch to turn on the light.

Later

Re: Lateral Thinking III

Posted: February 16th, 2009, 2:05 pm
by Holmes
That answer is denied. Sorry, you must enter the room, the problem says so.

Re: Lateral Thinking III

Posted: February 16th, 2009, 3:15 pm
by Sayumi
Pretty sure I know this one  ;D
Spoiler:
1.Turn on two of the switches
2.Wait for about 30min
3. Turn off one of the switches
4. Go into the other room

The 3 possibilities are:
-the light is on -> it is the switch which is still on
-the light is not but the lightbulb is warm when you touch it -> it is the switch you just turned off
-the lightbulb is not on and cold-> it is the third switch you never turned
5.Go out of the room and confidently answer the question  :D

Re: Lateral Thinking III

Posted: February 16th, 2009, 4:34 pm
by Holmes
Sayumi wrote: Pretty sure I know this one  ;D
Spoiler:
1.Turn on two of the switches
2.Wait for about 30min
3. Turn off one of the switches
4. Go into the other room

The 3 possibilities are:
-the light is on -> it is the switch which is still on
-the light is not but the lightbulb is warm when you touch it -> it is the switch you just turned off
-the lightbulb is not on and cold-> it is the third switch you never turned
5.Go out of the room and confidently answer the question  :D
Oh, my, that was quick. It is correct and very well thought. I really like step number 5.
Let´s see if others can do it.

Re: Lateral Thinking III

Posted: February 16th, 2009, 8:32 pm
by ayw
Spoiler:
Exploit the fact that a light bulb emits two types of 'information'. Light and heat. Switch on two of the three switches, say a and b, leave c off.  Wait a while, then switch off b. Go into the room. If the light is on and bulb is warm then a is the correct switch. If light is off and bulb is warm the b is the correct switch. Finally, if light is off and bulb is cold then c is the correct switch.
Then proceed to Sayumi's step 5.

Re: Lateral Thinking III

Posted: February 16th, 2009, 8:34 pm
by Holmes
ayw wrote:
Spoiler:
Exploit the fact that a light bulb emits two types of 'information'. Light and heat. Switch on two of the three switches, say a and b, leave c off.  Wait a while, then switch off b. Go into the room. If the light is on and bulb is warm then a is the correct switch. If light is off and bulb is warm the b is the correct switch. Finally, if light is off and bulb is cold then c is the correct switch.
Then proceed to Sayumi's step 5.
Exactly.  :)

Re: Lateral Thinking III

Posted: February 18th, 2009, 2:26 am
by sstimson
You could do the same with just one switch at a time.
Spoiler:
Turn on switch A and wait
Turn off Switch A and Turn on switch B
Enter Room

Light Warm it A
Light on it B
Light off and cold it C
Later