Gas Electricity Water puzzle can't be done?

lardom · 2012-04-13 06:24

Someone who works in the office at my job asked if I had seen 'The puzzle'. I couldn't resist. I 'knew' I could figure it out. The idea is that the three houses in the graphic must each recieve all three utilities - gas electricity and water without crossing any lines. You can't go under or over and you can't 'steal' from another house. Try as I might I could only complete eight lines. I'm not a purist so I had no problem Googling the puzzle when I suspected there was no solution.
Is there a solution or an explanation?

Publison · 2012-04-13 07:23

Answer:

Solar Panels on each house, rain water collection system, Liquid Propane tank at each house.

What did I win?

Jim

Ray0665 · 2012-04-13 07:41

The solution is to think three dimensional.
at least one of the lines goes around the page ==> front - edge - back - edge - front

Cheating? Maybe, but not disallowed by the puzzle rules.

lardom · 2012-04-13 07:45

Typical intelligent 'outside the box' forum answers!

idbruce · 2012-04-13 09:23

At first glance for this board layout, I think it can be done.

Bruce

Phil Pilgrim (PhiPi) · 2012-04-13 10:02

The board layout is not the same as the puzzle. In the board layout, you've "cheated" by having traces cross under the TO220 leads.

-Phil

idbruce · 2012-04-13 11:23

Phil

Ahh but the lead does not represent the inlet, the pad is the inlet

That would be like saying they cannot criss-cross throughout the house

idbruce · 2012-04-13 11:24

Give me a minute

idbruce · 2012-04-13 11:40

Is that under ad over the house, or other lines or both?

codeviper · 2012-04-13 11:48

here you go

Gas Electricity Water puzzle solution.jpg

turns out I overlooked where i had drawn the line I knew i mad the 9th connection unfortunatly i didnt pay attention to where

tonyp12 · 2012-04-13 11:54

>The answer to the strict puzzle posed above is no; It is impossible to connect the three cottages with the three different utilities without at least one of the connections crossing another
http://en.wikipedia.org/wiki/Water,_gas,_and_electricity

codeviper · 2012-04-13 12:01

tonyp12 wrote: »

>The answer to the strict puzzle posed above is no; It is impossible to connect the three cottages with the three different utilities without at least one of the connections crossing another
http://en.wikipedia.org/wiki/Water,_gas,_and_electricity

I resend what i said here earlier turns out I over looked where one of my lines went

xanadu · 2012-04-13 12:05

There's a solution that involves bending the rules but your drawing doesn't allow for it.

codeviper · 2012-04-13 12:12

I know but who wants to bend them when you can go in the rules and still win?
my solution works does it not?

not to bad considering i was in the back of a car heading down a bumpy road.

Phil Pilgrim (PhiPi) · 2012-04-13 12:12

codviper wrote:

look I DID IT!
ITS DONE SEE?

The house on the left did not get gas.

-Phil

idbruce · 2012-04-13 12:13

Thanks tonyp12

You just saved me lots of aggravation

codeviper · 2012-04-13 12:15

Phil Pilgrim (PhiPi) wrote: »

The house on the left did not get gas.

-Phil

lol sorry i over looked that thanks.
i am embarassed

localroger · 2012-04-13 12:31

This is a basic intro problem in topology. I recall reading somewhere that the problem can't be solved on a flat plane or sphere, but it can be solved if the cottages and utilities are located on a torus.

codeviper · 2012-04-13 12:52

that's nice and all and yes a torus is the perfect solution.
sorry i jumped on that one.

I love puzzles but the ones with no solution in the inherent structure drives me nuts, cause of course you can alter the puzzle and win, but we can always break or bend the rules.
but I like to remember the rubrix cube. the rules said " try to get all the colors to one side" but did it seem right to pull off the stickers.
i can also think this may work out if you printed this and folded it into the right shape.

pedward · 2012-04-13 12:56

codeviper wrote: »

look I DID IT!
ITS DONE SEE?

Gas doesn't go to the first house.

pedward · 2012-04-13 12:57

codeviper wrote: »

lol sorry i over looked that thanks.
i am embarassed

Don't worry, it's a trick question to begin with.

mindrobots · 2012-04-13 13:39

Kobayashi Maru, of course!

GordonMcComb · 2012-04-13 13:46

Yes, it's unsolvable on a flat plane. Also, any solution where a utility line is shared breaks the rule about not stealing from another house. There has to be a separate feed from each utility.

Some human resource departments give this puzzle to test problem-solving skills. They also use it on those expensive management retreats. They look for such things as trying to re-arrange the houses and utilities (the puzzle still can't be solved). Those who try to rearrange the objects usually get a higher "grade" than those who keep the layout the way they got it. That supposedly shows a higher degree of problem-solving. Those who present a solution that "cheats" get a failing grade. They're looking for problem solving within a framework (i.e. within budget, in time, etc.).

-- Gordon

codeviper · 2012-04-13 16:16

If a Job was in question no doubt I will alter the rules to win and then say "you did not specify I could not alter the ________" I have done it.
yet I love puzzles that has the solution and I have to comply with the rules.
MENSA books are fun ^,^
yet if I see something presented as a puzzle I like to have it possible to win within the structure.
though thinking of it for a moment the rules do not say you can not print this and roll it into a cylinder does it?
that may work too.
some my argue you can not alter the real world, yet in a way you can.
anyone going to enter the contest? Parallax is in on it, just a reminder

Martin_H · 2012-04-13 18:06

I haven't drawn this on paper, but it seems like the seven bridges puzzle. Basically topology says that only two vertices can have an odd number of lines emanating from them, while other vertices must have an even number. Here you have six nodes with three lines each and that is not going to work.

Franklin · 2012-04-13 22:03

http://www.youtube.com/watch?feature=iv&src_vid=xu_V-Uv6ykY&v=ODtwehGzoLM&annotation_id=annotation_999734

skylight · 2012-04-15 12:18

It's a puzzle we used to show at school many moons ago and it is impossible bar cheating, reminds me of the paper folding one where no matter how big a sheet of paper you start off with you cannot fold it in half more than eight times only using your hands,

Gadgetman · 2012-04-16 03:53

skylight wrote: »

It's a puzzle we used to show at school many moons ago and it is impossible bar cheating, reminds me of the paper folding one where no matter how big a sheet of paper you start off with you cannot fold it in half more than eight times only using your hands,

Seen Mythbusters?
With a large enough sheet of paper you CAN get more folds...

The 3 houses/3 utilities problem is written down in a lot of books dealing with topologies, so quite familiar to me.

Anyone who wants to play with topologies, and especcially planar graphs should check out
http://www.planarity.net
When you pass 50 nodes in the graph it suddenly begins to get challenging...

Microcontrolled · 2012-04-16 04:46

I give this puzzle to people all the time, it's fun to see them trying to figure it out.

If they ask for the solution, I run the final line over to the back side of the paper, then poke a hole next to the house and run it back through. It's cheating, yes, but it's good for laughs.

skylight · 2012-04-16 07:14

Be interesting to see that episode of mythbusters and they just used their hands and no devices to fold?

Mark_T · 2012-04-16 09:19

The 'standard' solution to the puzzle is to route one of the utilities through the middle of another property - which is not quite as cheating as commoning two of the properties with the same supply. I think the trick allows an unlimited number of utilities and properties to be solved so long as the properties are large enough to route pipes/wires through.

Gas Electricity Water puzzle can't be done?

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