re: Wanna make a 100g? Solve a problem!
by 2b on 2009/05/10 13:59
So this was a simple problem presented to students in MIT.
First one to give me the correct answer and how they came up with it I'll give 100g to. But don't guess the answer isn't that complex and you can probably guess it. It's why you got it that will earn you the gold.
So here it is:
A bus runs 2 routes all day long.
From point B to point A and back and it takes 4 minutes.
After he goes from point B to point C and back and it takes 12 minutes.
(sort of like an 8! back and forth all day long.)
If you go to point B at any given point of the day. What would be the average wait time until the bus comes there?
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2bRaider
Joined: 17 Jul 2008 Posts: 34
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re: Wanna make a 100g? Solve a problem!
by Jatone-Takall on 2009/05/10 15:51
5.5minutes
There are 4 (general) possibilities.
1) You arrive at B and the bus just arrived at A. 2 minute wait.
2) You arrive at B and it just left for A. 4 minute wait.
3) You arrive at B and it just arrived at C. 6minutes.
4) You arrive at B and it just left for C. 12minutes.
The average wait time for the bus going to point A and back is 3,
(2+4)/2 = 3.
The average wait time for the bus going to point C and back is 8,
(6+12)/2 = 8
So your average wait time for any given point of the day when you get to point B is 5.5, (3+8)/2 = 5.5.
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re: Wanna make a 100g? Solve a problem!
by 2b on 2009/05/10 16:45
that answer is incorrect.
the question is if you go to B at any point of the day what the wait time would be.
i'll give hints if people give up and nobody wants to try anymore.
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2bRaider
Joined: 17 Jul 2008 Posts: 34
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re: Wanna make a 100g? Solve a problem!
by Klarya on 2009/05/10 16:53
its 4 minutes...because if the bus is at point A then it will be 2 minutes for it to get to B and if its at C its 6 minutes back. So at any given time of the day theres a potential of waiting 4 minutes.
_________________ Hero's don't need luck....they need a pally
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Klarya
Joined: 10 Mar 2008 Posts:
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re: Wanna make a 100g? Solve a problem!
by 2b on 2009/05/10 17:03
that would be too simple 4 would be too simple
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2bRaider
Joined: 17 Jul 2008 Posts: 34
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re: Wanna make a 100g? Solve a problem!
by Kobetauren on 2009/05/10 18:39
Quick obvious guess: 8 minutes. (4/2)+(12/2)=8
But it doesn't feel right.
_________________ Having posts deleted moved where no one can read them since February 2009
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re: Wanna make a 100g? Solve a problem!
by Jatone-Takall on 2009/05/10 18:46
how does the routes work, does the bus have to go to A to B to C to B to A? or can it go C to B to C to B to A?
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re: Wanna make a 100g? Solve a problem!
by 2b on 2009/05/10 20:29
8 and 4 are both wrong answers
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2bRaider
Joined: 17 Jul 2008 Posts: 34
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re: Wanna make a 100g? Solve a problem!
by Zenyatta25 on 2009/05/10 20:45
My guess 36 minutes.
I don't do math like the normal joe. I tend to go the long way around.
If when going in one direction Point B is the 4 minute mark point A is the 2 minute mark and going the other, Point B is the 12 minute mark, Point C is the 6 minute mark.
If when you get to the station B and the bus just left 1 minute ago on the 4 minute route, you have 3 minutes remaining. If it left 2 minutes ago there are 2 minutes remaining. And same the other direction. If you use each equal distance amounts as a 1 minute marker around his route and you lay that out you'd get...
Minute Point - Minutes Remaining
1.....................................3
2.....................................2
3.....................................1
4.....................................0
1.....................................11
2.....................................10
3.....................................9
4.....................................8
5.....................................7
6.....................................6
7.....................................5
8.....................................4
9.....................................3
10...................................2
11...................................1
12...................................0
You add up the minutes remaining column and take the average which comes to 36.
EDIT: This thing doesn't like spaces very much
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re: Wanna make a 100g? Solve a problem!
by 2b on 2009/05/10 20:52
if the average wait time for going 1 way is 2 mins and going the other way is 6 mins the average is gonna be somewhere in between
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2bRaider
Joined: 17 Jul 2008 Posts: 34
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re: Wanna make a 100g? Solve a problem!
by Zenyatta25 on 2009/05/10 20:55
I told you before... I DON'T DO MATH I'm too damn creative for math.
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re: Wanna make a 100g? Solve a problem!
by 2b on 2009/05/10 21:01
i'm not creative at all so i do math
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2bRaider
Joined: 17 Jul 2008 Posts: 34
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re: Wanna make a 100g? Solve a problem!
by Zenyatta25 on 2009/05/10 21:06
Well to come up with my conclusion like I did, I drew out little diagrams instead of mathematically figuring it out.
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re: Wanna make a 100g? Solve a problem!
by 2b on 2009/05/10 21:09
i'll wait a couple of days to see if anybody can solve it or care to actually try and i'll post the answer. i don't know how many people give a shit since most people despise math.
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2bRaider
Joined: 17 Jul 2008 Posts: 34
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re: Wanna make a 100g? Solve a problem!
by Songi on 2009/05/10 22:25
Any point of the day? Is that even calculable? The Average wait time is random.
but if I was to do a math problem in my head I would guess 4.5 minutes. Average.
_________________ THIS IS GEC
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SongiRaider
Joined: 22 Sep 2008 Posts: 225
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