# Homework puzzle from 15 years ago never solved -

1. Jul 11, 2004

### charmed1j

I had this puzzle in one of my math classes in Jr. High - for 15 years I have been trying to solve it - noone would ever give me the answer, and I was sick on the day the teacher gave it. He has since retired, and noone from my class remembers how to do it. Please help! LOL
I am tired of killing trees by wasting paper on it.
Jennifer Vogt
charmed1@chartermi.net

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2. Jul 11, 2004

### charmed1j

OOps shound mention, can only do through each door once, and you have to use one continuous line.

3. Jul 11, 2004

### Zorodius

It says the attachment is "pending approval", and I can't open it, but your question is probably about a subject called "Topology", specifically the topology of networks, and the solution to your problem is probably what is called a "Euler Path".

In order for such a path to exist, there can only be two vertices with an odd number of connections. Because, if your line enters a vertex, then it must leave the vertex as well, unless it is beginning or ending at that vertex. It's entirely possible that the problem you were given does not meet those criteria, and so it is not solvable.

4. Jul 11, 2004

### charmed1j

I have no idea what you just said, lol
I just know there is supposedly a solution for this one.

5. Jul 11, 2004

### Math Is Hard

Staff Emeritus
Hey Zorodius- are you like psychic or something? I am going to be really impressed if your solution matches a problem you can't even see!
cool!

6. Jul 12, 2004

### kuengb

I think the problem is indeed not soluble. It consists of five rooms (six if you count the outside too) and doors in between. As Zorodius said, if the line enters one room it has to leave it again. The only exceptions are the rooms where the line starts or ends. These two rooms have an odd number of doors, the others must have an even number. Here you have three rooms à five doors, plus the "outside room" which has nine doors, that's too many. As far as I counted right

PS Math is Hard: Impressing avatar change :rofl:
OK this is possibly one real attractive Skunk, but I'm not the guy to decide about this.

Last edited: Jul 12, 2004
7. Jul 12, 2004

### Zorodius

There is no solution by the terms of the problem. It's probably meant as an insipid "think outside the box" exercise where you are supposed to come up with some alternate interpretation of the problem that permits it to be solved, like poking a hole through the paper and drawing on the back side, or erasing previous lines as you draw new ones, or using a piece of string that is held in the air instead of an actual line, and so on.

8. Jul 12, 2004

### Math Is Hard

Staff Emeritus
awwww.. thanks!

9. Jul 12, 2004

### cronxeh

well the thing seems perfectly symmetrical.. fold that paper and you have your solution. think in 3D, rotate, adjust, tip over.. think harder.. right down the solution

10. Jul 13, 2004

### krab

There are many such problems. Google on "The Bridges of Konigsberg", for example.

11. Jul 13, 2004

I was just looking through a old crappy algebra book and I saw the exact same question. Dont know what the sol. is, just thought Id stop and say that I saw the question in an old crappy book. good luck

12. Jun 30, 2011

### prajkir

Dont understand the question. what is the question.

13. Jun 30, 2011

### SammyS

Staff Emeritus

The problem was 15 years old, 6 1/2 years ago, so I doubt that you'll have any luck.

14. Jun 30, 2011

### Staff: Mentor

It would appear that the problem is to find a single closed path through the maze that passes through each "door" exactly once.

15. Jul 1, 2011