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#21 wolfgang

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Posted 16 September 2011 - 08:50 AM

I`ll give another example, in more details:
....................................................Arrival.............................................Departure..............................
Left side........................................6:00...................................................6:01..................................
Right side......................................6:01...................................................6:02..................................
6:03.................No train............
6:04.................No train............
6:05.................No train............
6:06.................No train............
Left side.......................................6:07....................................................6:08..................................
right side......................................6:08....................................................6:09..................................
and so on................
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#22 bhramarraj

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Posted 16 September 2011 - 11:25 AM

In the original question it looks as if one train comes on the station at say 6:00 from left side, then another train comes from left side at 6:4.
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#23 thoughtfulfellow

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Posted 16 September 2011 - 02:19 PM

I was sitting in a subway station No. 12(toatal stations are 24).
On this line are several trains transporting passengers from staion(No. 1 ) till the end station( No. 24),then each train will continue the journey from side to side(both sides are connected together at each end).I noticed that after each 4 Minutes a train arrives this station from left side toward the right side,one minute later another train arrives the station but to the opposit direction,and so on.
If each train stays in each station exactly one minute( notice that the train at each end will make a curve and return back to that staion,just like a circle).
Howmany trains are there on this line?

I`ll give another example, in more details:
....................................................Arrival.............................................Departure..............................
Left side........................................6:00...................................................6:01..................................
Right side......................................6:01...................................................6:02..................................
6:03.................No train............
6:04.................No train............
6:05.................No train............
6:06.................No train............
Left side.......................................6:07....................................................6:08..................................
right side......................................6:08....................................................6:09..................................
and so on................

Hence, I agree with bhramarraj that this would mean, in your example above, that the next train from the left would arrive at 6:04. Did we loose something in translation?
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#24 capecchi

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Posted 16 September 2011 - 04:46 PM

I agree there's something that needs to be cleared up. In the original post it sounds as if trains are arriving FROM THE LEFT every 4 minutes. The first example posted by wolfgang then makes it seem that trains arrive FROM THE LEFT every 5 minutes. Now this most recent example shows they arrive FROM THE LEFT every 7 minutes.
So the question that needs to be clarified: How often do trains arrive FROM THE LEFT?
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#25 Phaze228

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Posted 17 September 2011 - 12:14 AM

I`ll give another example, in more details:
....................................................Arrival.............................................Departure..............................
Left side........................................6:00...................................................6:01..................................
Right side......................................6:01...................................................6:02..................................
6:03.................No train............
6:04.................No train............
6:05.................No train............
6:06.................No train............
Left side.......................................6:07....................................................6:08..................................
right side......................................6:08....................................................6:09..................................
and so on................


To be curt...
is it
Train to station = 4 minutes
Stationed train = 1minute
Opposite train arrival = the time of the departing train
Train curving from station 24 to the original station (No.1 infer) = 5 minutes?

Edited by Phaze228, 17 September 2011 - 12:14 AM.

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#26 amonkkilla

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Posted 17 September 2011 - 01:05 AM

i know its a trick question HAHAHAHAHAHA! good one
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#27 wolfgang

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Posted 17 September 2011 - 04:07 PM

Hence, I agree with bhramarraj that this would mean, in your example above, that the next train from the left would arrive at 6:04. Did we loose something in translation?

Sorry about the mistake...this example is the right one...i.e. 2 trains(left then right,in one minute interval),then 4 minutes(No trains),and so on.
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#28 capecchi

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Posted 17 September 2011 - 06:37 PM

Alright then. If the new example is correct and minute by minute we go: train from left, train from right, no train, no train, no train, no train, train from left, etc. Then We need to solve:
23x+24=6n and
25x+24=6m
This gives 23m=25n-8
Which has a solution of m=n=4 but this again gives x=0 so if we want the first set of integers that give us a nonzero transit time we find:
m=29,n=27. This gives x=6 minutes. So the track has 56 trains, each 6 minutes apart. For explanation of what I did here see my first post.
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#29 thoughtfulfellow

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Posted 18 September 2011 - 12:54 AM

I (and, I think others) have made a false assumption:
Spoiler for False assumption made

Spoiler for Solution

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#30 wolfgang

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Posted 18 September 2011 - 04:12 PM

I (and, I think others) have made a false assumption:

Spoiler for False assumption made

Spoiler for Solution

If they are 25 trains,,,and there are only 24 stations,,,that means there should be only one minute interval between train and the next one,and with the extra train (No.25) would be no interval between it and the next train.
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