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## #1 2006-05-25 07:35:40

bryan
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### tough one

you have to get heat water and eletric to each house but no lines can cross

heat                      water                    eletric

house 1                        house2                          house3

you can use a infinte amount of paper

## #2 2006-05-26 02:11:42

mathsyperson
Moderator

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### Re: tough one

Heehee, I do decision maths so I can prove that that's impossible. =P

Why did the vector cross the road?
It wanted to be normal.

## #3 2007-03-13 13:56:49

JaneFairfax
Legendary Member

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### Re: tough one

Okay, I’ve been looking at some of these very old threads here …

And I’ve seen this puzzle before. Here is the solution:
http://puzzles.nigelcoldwell.co.uk/twentysix.htm

Q: Who wrote the novels Mrs Dalloway and To the Lighthouse?

## #4 2007-03-13 15:49:37

Ricky
Moderator

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### Re: tough one

I think that is a cheap way out.  Represent each house as a vertex.  Now try it.

"In the real world, this would be a problem.  But in mathematics, we can just define a place where this problem doesn't exist.  So we'll go ahead and do that now..."

## #5 2007-03-13 15:57:02

JaneFairfax
Legendary Member

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### Re: tough one

Then Euler’s formula comes into play.

http://en.wikipedia.org/wiki/Planar_gra … 7s_formula

Q: Who wrote the novels Mrs Dalloway and To the Lighthouse?