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Q: Running into ex partner in town ( No Answer,   13 Comments )
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 Subject: Running into ex partner in town Category: Science > Math Asked by: geelong121-ga List Price: \$10.00 Posted: 12 May 2006 00:31 PDT Expires: 11 Jun 2006 00:31 PDT Question ID: 727992
 ```I live in Geelong, Victoria, Australia Area : 1,240 kmē 2006 :205,000 (urban) Density : 165.3/kmē What is the statistical chance of every running into them on any given day? That is what is the likelihood of going into town, and walking down a Street and seeing them in the same street, building etc(where ever I am) Is there a math formula that can be applied to work out the probability of this happening? What are some of the variables that I can employ to minimise the chances of this happening (obviously not going where they would normally go), when you take in account that I have no idea where they could be at any given time in relation to where I am.```
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 Subject: Re: Running into ex partner in town From: redfoxjumps-ga on 12 May 2006 00:44 PDT
 ```The assumption the someone else or even yourself will be in a random spot in a city is fairly silly. While you can not guess which grocery store they will visit, chances are they will visit one sometime during the week. On the other hand a visit to the dump or the sewage works would seem unlikely for you both. (Density meant population or building density.?)```
 Subject: Re: Running into ex partner in town From: probonopublico-ga on 12 May 2006 01:01 PDT
 ```Sod's Law says that you will meet your Ex in the unlikeliest place and in the most embarrassing circumstances imaginable. It's probably best to grow a beard. Or, if you've already got one, to shave it off. (I am, of course, assuming that you are a man. Women can change their appearances like nobody's business with a new hairdo or whatever.)```
 Subject: Re: Running into ex partner in town From: frde-ga on 12 May 2006 04:37 PDT
 ```If you convince yourself that you will run into her - and look forward to it - then the chances are vastly reduced There is also the 'skulk' factor, if she does not want to meet you, she'll pretend not to see you, or hide behind a display in a supermarket.```
 Subject: Re: Running into ex partner in town From: probonopublico-ga on 12 May 2006 05:58 PDT
 ```There is also the 'Stalk' Factor. Maybe she does want to meet you again. Hoping that just maybe ... It's back to old times.```
 Subject: Re: Running into ex partner in town From: geelong121-ga on 12 May 2006 06:34 PDT
 ```redfoxjumps-ga on 12 May 2006 00:44 PDT Density meant population or building density.?) I assume "denisity" means people per square kilometer 165.3 It may sound silly, but i thought there might be a mathematical approach to this quesion. (Maths is not my thing)```
 Subject: Re: Running into ex partner in town From: myoarin-ga on 12 May 2006 07:26 PDT
 ```I think the chances are much greater than population density would suggest, because you both will only go to certain areas of a city you are familiar with, even if you both don't want to happen to run into each other. The skulk factor may help avoid this, but for my thinking, if one of you spotted the other, that would count as an incident of "the likelihood of going into town, and walking down a Street and seeing them ..."```
 Subject: Re: Running into ex partner in town From: geelong121-ga on 12 May 2006 08:17 PDT
 ```From: myoarin-ga on 12 May 2006 07:26 PDT "I think the chances are much greater than population density would suggest, because you both will only go to certain areas of a city you are familiar with, even if you both don't want to happen to run into each other. The skulk factor may help avoid this, but for my thinking, if one of you spotted the other, that would count as an incident of "the likelihood of going into town, and walking down a Street and seeing them ..." I guess thats just it, i am tied of "skulking" I was hoping for a logical mathematical expression, like 1 in 1 million. (in fact 1 in 205,000) but I do appreciate peoples comments```
 Subject: Re: Running into ex partner in town From: rracecarr-ga on 12 May 2006 10:03 PDT
 ```Let's say on a typical day in town, you see 500 people (walking down the street, in a shop, whatever). That is about 1/400 of the population. So 1 chance in 400 seems like an ok guess.```
 Subject: Re: Running into ex partner in town From: geelong121-ga on 13 May 2006 01:00 PDT
 ```Sorry does not look like this is going to get answered. (Perhaps its a silly question). Is there anything I can do to fully qualify the question. Up the price? I like the "sod's" law concept. I am trying to avoid it. Perhaps probabilities, statistics, etc are not the answer.```
 Subject: Re: Running into ex partner in town From: myoarin-ga on 13 May 2006 04:30 PDT
 ```G'day, again. Increasing the price would maybe give you some interesting statistics, but for your individual problem, I doubt that this would help you very much. You might try to anticipate what could occur if you meet and plan your response, considering that it will probably be in public, maybe in the presence of someone who knows you (no good trying to claim that you are not the person she thinks).```
 Subject: Re: Running into ex partner in town From: geelong121-ga on 16 May 2006 13:17 PDT
 `Any Maths whizz'es care to have a stab!`
 Subject: Re: Running into ex partner in town From: stanmartin1952-ga on 24 May 2006 13:36 PDT
 `You might consider running into them enough until it doesn't bother you anymore.`
 Subject: Re: Running into ex partner in town From: activealexaoki-ga on 11 Jun 2006 15:26 PDT
 ```LOL It is funny to read no one is answering mathematically. Only sociological perspectives. Although it is mathematically challenging, even inpractical to calculate. From the first sight, you gave the area/population/residencial density (probably of night time). But all those variables are irrelevant, of my opinion. The reason behind my claim is that you need a variable where people have available access, such as streets... or park. Let me assume the only varialbe to consider is the streets. Applying the basic idea Graph Theory, you can simplify your city. First you map the streets with straight lines and crossings with intersections. (Since I checked "Geelong, Victoria, Australia" is mesh streets, you may estimate by drawing straight lines, like a mesh.) Suppose you start walking from a intersection where you can choose 1 direction out of 4 direction. If your selection is random, the probability of choosing 1 out of 4 direction is .25, leaving the probabilities of choosing other streets in the city (other than those 4 to consider) be 0. At next intersection, you find another probability of choosing one direction to another, namely 1/n where n is the number of option and n is always 4 inside a mesh, and others be 0. After making decisions (X times) for all the streets you walk. For a person you keep eye on meeting again, he/she has 4^i options in total. By reasoning backward, you will see that his/her last direction is definite. If he/she does not decide to go back the street he/she came from, number of his/her choosing streets must be (N+X-1,X), which is the combination of selections with unlimited repetition. Thus the probability of him/her reaching the street you chose at the end is (N+X-1,X)/4^i where N is the number of all street blocks, and X is the number of times you chose. The answer, of meeting the person again, is the product of two probability. In this case, [(N+X-1,X)/4^i]*[PI_{k=1}^{X} :x:_{k}] where :x: is the probability {Prob(choosing a street at x_{k})=:x:_{k} | k=1,...X} Another variable which you may consider would be restricted area, like office buildings, etc. The probability can be estimated by the product of getting hired by the same employer and assigned to the same floor as the person. Of course, it assumes the employment for both of you is independent. So it is really difficult question to answer mathematically but I think you felt the sense.```