Feb 2011 puzzles **16KB PIC**

[bill bolton]

You are correct.....

That solution will not work with cold light sources, so its only correct if you explicitly specify incandescent blubs in the problem statement...

Cheers,

Bill B.

[AMATX]

The heat, right! The puzzle seemed so familiar, I knew I saw it before. This time, I will not forget the solution. As for the hanging person, I have no ideas.

I'll leave you 'hanging' on this one for a while, then post a response later. However, this one is somewhat well known, so I'd expect an answer...

[craigmontHunter]

I have the answer - it is ice (well water) - the guy stood on a big block of ice, which then melted, creating a puddle of water on the floor.

Now I have one - "The train that leaves tommorow is a mile upon its way, because the train that left tommorow, it left yesterday"

How is this possible

[automobus]

How does a person in prison get that much ice?

Does the train puzzle involve daylight saving or the date line?

[AMATX]

Ice is correct...wouldn't need that much, either, just enough...

I'd guess the international date line is involved with the next puzzle.

[craigmontHunter]

just enough ice to give a few inches of drop - it would be slow though. No, the IDL does not have anything to do with it

[AMATX]

I suppose if the train were lonnnnnng enough, it was right around midnite, and you were on the edge of two different time zones(doesn't have to be IDL), one could end up with a train coming and going, eh?

[rkawakami]

That solution will not work with cold light sources, so its only correct if you explicitly specify incandescent blubs in the problem statement...

Name a common cold light source which...
a) plugs/screws into a regular light fixture one would typically find in a home and
b) does not radiate any heat which a human hand could not detect

The only thing that that might qualify would be an LED bulb. However, I would think with the power supply in the base, there's going to be enough heat emitted that would raise the bulb slightly higher than the ambient temperature of the attic. Even so, to ensure the best chance for this method to work, do the switch experiment in the early morning when the attic is the coolest.

Fluorescent tubes do throw off enough heat to be felt even after they are turned off for a minute or two. Same goes for the screw-in FL replacement bulbs (coiled or multiple-tower designs). And no, endoscopes or fiber optics do not qualify

[Marin85]

Ok, now it is my turn The set-up is the same as the one of Harryc, with the only exception that you don´t have any tools available, no wires, no ice, no nothing, nor there is any heat produced by the light sources! In other words, you have only you, the three switches next to you, and the three light sources in the attic which you don´t have any visual contact to. How do you go about this now?

You are alone at home and can't ask anyone for help. There are three switches downstairs where you are standing. Each corresponds to one of the three light bulbs in the attic. You can't see the attic from where the switches are located. You can turn the switches on and off and leave them in any position. How would you identify which switch corresponds to which light bulb, if you are only allowed one trip upstairs?

Furthermore, based on answers to questions posed in this thread;
Each switch is connected to and controls (turns on and off) one of the bulbs in the attic. The house and all outlets/switches have power. The bulbs are working and light up.

[AMATX]

The 'problem' with this puzzle is in tightly defining the conditions of the test.

LED bulb, incandescent, ?

Tools, no 'tools' ?


The various solutions involve a state change of one of the bulbs(the AHA! moment to the puzzle) and the rest is easy. So, warm/hot bulb, away we go.

Marin's setup is still open enough to have loopholes big enough to drive a truck through:

* State change #1 of 1st bulb: set light switch to the halfway point, hoping the light will flicker when you go check it out. Now we've dealing with a state change that's not temperature, but light; ala flickering.

* Time: no time limit? Ok, turn on one light, wait forever until it burns out, then examine the three bulbs to see which looks burnt out. There you go, another 'state change'...

* Other half-bakes solutions involve things like turning on two lights, positioning something(prop, rubber band, etc) to flip off one of the switches when you're looking at the two lights. Or, hooking up a gizmo to one swich to vary the juice so that one light glows dimmer/brighter than the other.

With three choices to decode and only ONE action to take, it's impossible to solve without fudging around the edges/fringes...but, hey, it's a PUZZLE, folks

[Harryc]

... turn on one light, wait forever until it burns out

That was my thought too. Turn on switch one and wait a year for the (incandescent bulb) to burn out. Turn on switch 2 and go upstairs into the attic. So now you've identified switch/socket #2 because it is on. Take the non-lit bulbs and try them in switch #2's socket. The one that does not light is from switch/socket #1 (because it is burned out). The one that lights is from switch/socket #3. Now all have been identified.

[Marin85]

Marin's setup is still open enough to have loopholes big enough to drive a truck through:

* State change #1 of 1st bulb: set light switch to the halfway point, hoping the light will flicker when you go check it out. Now we've dealing with a state change that's not temperature, but light; ala flickering.

* Time: no time limit? Ok, turn on one light, wait forever until it burns out, then examine the three bulbs to see which looks burnt out. There you go, another 'state change'...

* Other half-bakes solutions involve things like turning on two lights, positioning something(prop, rubber band, etc) to flip off one of the switches when you're looking at the two lights. Or, hooking up a gizmo to one swich to vary the juice so that one light glows dimmer/brighter than the other.

NO! Unlike all the other "puzzles" this one is asking for an internal solution to the given problem. You are introducing new stuff into the set-up, all of this is not mentioned in the set-up and thus is not allowed to be used! I know, people like to be picky about stuff like this, still... Once again: all you are allowed to use is within the set-up, it is self-contained! In particular, here are some things that are not mentioned in my set-up and thus cannot be used:
- assumptions of crappy switches that cause light flickering;
- bulbs burning out (strictly speaking from your point of view, I don´t mention anywhere food, do I?!... );
- prop, rubber band and similar are considered here tools/devices/utilities/gizmos...;

With three choices to decode and only ONE action to take, it's impossible to solve without fudging around the edges/fringes...but, hey, it's a PUZZLE, folks

Please read the question carefully! No edges or fringes, just a practical task where all you can use is your head Hint: nothing is impossible. And yes, it is hard, in particular because one is not allowed to use external stuff (e.g. things not mentioned in the set-up).

And no, the puzzle does not involve any sci-fi, psycho, supernatural etc. stuff!

[automobus]

The three bulbs are incandescent. The three switches are dimmer switches. One off, one half way, one on full. Solved.

[Marin85]

The three bulbs are incandescent. The three switches are dimmer switches. One off, one half way, one on full. Solved.

Yeah, but NO Where do you find any assumptions about the nature of the switches and the bulbs in my set-up? Besides, the question is not about the bulbs and the switches, but about what you do

[emtee3511]

Man's Best Friend (taken from the "Real Man Test")

This is a multiple choice question where the correct answer is Answer C -- you have to fill in the blank for Answer C --

The best pet for a real man is:
a. A Dog
b. A Cat
c. A D T E C
(this is the correct answer -- I have given a hint with the first letter of each word in the correct answer) --

[RealBlackStuff]

a devouring b

[Harryc]

a devouring b

Said differently - A Dog That Eats Cats

[emtee3511]

@RBS & Harryc -- Yep! A Dog That Eats Cats -- My husband loves that one (He doesn't love my five pound dog that runs from cats!) -- Okay, Question Two from the Real Man Test -- Again, Answer C is the correct answer --

A real man is stopped on a quiet country road by a flying saucer in the middle of the road. The space alien gets out, greets the real man, and presents him with a gadget. The space alien tells the real man that this small gadget has the power to end poverty, hunger, war, and in fact, all human suffering...

The real man:
A. Takes the gadget to the President of the United States.
B. Takes the gadget to the head of the UN.
C. TTGA

I am absolutely sure that most members of this Forum (male or female) would not only know this answer, but would do the exact same thing the real man would do

[AMATX]

Ok, now it is my turn The set-up is the same as the one of Harryc, with the only exception that you don´t have any tools available, no wires, no ice, no nothing, nor there is any heat produced by the light sources! In other words, you have only you, the three switches next to you, and the three light sources in the attic which you don´t have any visual contact to. How do you go about this now?

You are alone at home and can't ask anyone for help. There are three switches downstairs where you are standing. Each corresponds to one of the three light bulbs in the attic. You can't see the attic from where the switches are located. You can turn the switches on and off and leave them in any position. How would you identify which switch corresponds to which light bulb, if you are only allowed one trip upstairs?

Furthermore, based on answers to questions posed in this thread;
Each switch is connected to and controls (turns on and off) one of the bulbs in the attic. The house and all outlets/switches have power. The bulbs are working and light up.

Ok, I'll bite(again). IF you are eliminating ALL sources of help(people, lighting, sound, etc) and all gadgets, etc.(different bulbs, blah blah blah), then this would not be doable. You need a minimum of TWO state changes between the bulbs to map the THREE of them one-to-one to the switches. That is, if you start out in one room w/switches and only have one trip to the other room w/bulbs.

So, any 'answer' to this probably involves some hidden thing or procedure not yet mentioned...

[RealBlackStuff]

Take The Gadget Apart, don't we all just LOVE tinkering...

[emtee3511]

@RBS - "don't we all just LOVE tinkering... Yep!

I'm outta here -- the real puzzles are waaaaaaaaaaaay to hard for me --

[automobus]

this small gadget has the power to end poverty, hunger, war, and in fact, all human suffering...

I would press the button immediately.

No dimmer switches? So they are ordinary two-position switches?
In a quiet room, I can usually hear the sparks inside a switch, when slowly moved to the very point where the circuit is closed. And if I am the only one in the building, I expect it will be quiet enough to hear the spark.

Set the switches so one switch in the odd position. Go up, associate the odd bulb with the odd switch. Remove one of the identical two bulbs. Back by the switches, carefuly toggle and listen to determine which is connected to the empty socket and which has the bulb. Solved.

[Marin85]

Ok, I'll bite(again). IF you are eliminating ALL sources of help(people, lighting, sound, etc) and all gadgets, etc.(different bulbs, blah blah blah), then this would not be doable. You need a minimum of TWO state changes between the bulbs to map the THREE of them one-to-one to the switches. That is, if you start out in one room w/switches and only have one trip to the other room w/bulbs.

I am glad you did bite again Indeed, that is the correct setup! And indeed this is what theory tells us (and as much as trivial it may sound, it is also important realization), but this is a practical task. One needs an approach to the problem although it appears to be impossible.

So, any 'answer' to this probably involves some hidden thing or procedure not yet mentioned...

Not at all! (In particular, that is one of the reasons why it is hard.)

Set the switches so one switch in the odd position. Go up, associate the odd bulb with the odd switch. Remove one of the identical two bulbs. Back by the switches, carefuly toggle and listen to determine which is connected to the empty socket and which has the bulb. Solved.

Hmm... unfortunatelely, not everyone is supposed to be able to hear electricity

[craigmontHunter]

Hmm... unfortunatelely, not everyone is supposed to be able to hear electricity

Actually, if you very slowly flip the switch, you can hear the spark jump (and if you are really trying, you can see the sparks through the faceplate )

Or, if there is a light on in the room you are in, you may see it flicker when you turn on the filled socket, but not with the empty one (assuming that your house has a poorly wired fuse box).

[rkawakami]

Which brings up an important safety tip... if you smell a natural gas leak, don't turn on or off any electrical switch.

[automobus]

Or, if there is a light on in the room you are in, you may see it flicker when you turn on the filled socket, but not with the empty one (assuming that your house has a poorly wired fuse box).

There is another idea! Thank you for backing me up about hearing the spark.

I have another idea, but I guess a magnetic compass falls under the banned tools category.

[AMATX]

Note that I listed 'sound'(intentionally) in my little elimination list.

I suppose I should have included outrunning electrons, too, but I -@ss-ummed that no one on this board can run faster than electrons zinging down a wire to a light bulb

[bill bolton]

Name a common cold light source which...
a) plugs/screws into a regular light fixture one would typically find in a home and

Neither the type of light or the type of fixture was specified in the problem statement, so "regular fitting" would have to be an assumption made beyond the problem statement.

b) does not radiate any heat which a human hand could not detect

The the ability to physically access the light source also wasn't specified in the problem statement, which only went as far as indicating that the lights were observable only when actually in the remote space.

The only thing that that might qualify would be an LED bulb. However, I would think with the power supply in the base, there's going to be enough heat emitted that would raise the bulb slightly higher than the ambient temperature of the attic.

The "power supply" could well be elsewhere in the roof cavity and doesn't need to be immediately adjacent to the "light". That is the case for the LED lights in our house.

Cheers,

Bill B.

[AMATX]

...

Please read the question carefully! No edges or fringes, just a practical task where all you can use is your head Hint: nothing is impossible. And yes, it is hard, in particular because one is not allowed to use external stuff (e.g. things not mentioned in the set-up).

And no, the puzzle does not involve any sci-fi, psycho, supernatural etc. stuff!

Ok, Marin, time to come in from the cold and lay the answer upon us...enquiring minds gots to knowed...

[automobus]

Yes, tell us!

In the mean time, I thought of another incorrect solution. Like my other ideas, it requires unmentioned equipment and assumptions.

Switches: two in common position, one odd. On the way up, fetch water. In attic, associate odd fixture with odd switch. What follows is rather unsafe. Get water into one of the other two fixtures. After a significant amount of time, by capilary action, the water will make its way down the wiring. Back by the switches, using tools if necessary, determine which circuit is waterlogged. Solved.