## Welcome to BrainDen.com - Brain Teasers Forum

 Welcome to BrainDen.com - Brain Teasers Forum. Like most online communities you must register to post in our community, but don't worry this is a simple free process. To be a part of BrainDen Forums you may create a new account or sign in if you already have an account. As a member you could start new topics, reply to others, subscribe to topics/forums to get automatic updates, get your own profile and make new friends. Of course, you can also enjoy our collection of amazing optical illusions and cool math games. If you like our site, you may support us by simply clicking Google "+1" or Facebook "Like" buttons at the top. If you have a website, we would appreciate a little link to BrainDen. Thanks and enjoy the Den :-)
Guest Message by DevFuse

55 replies to this topic

### #51 Trainspotterx

Trainspotterx

Newbie

• Members
• 6 posts

Posted 02 October 2011 - 09:02 PM

Okay - because the gaps are 6 mins - confirmed I could be boring and guess all multiples of 6 but the answer must lie in why the trains from each direction are a minute out of sync.

This must be caused by the terminals 1 and 24. I have assumed incorrectly that they do not stop for a minute each side of the loop.

If in fact they do and trains stop for 1 minute each direction then I go back to my 94 minutes but add on the extra minute for each end thus arriving at 96 minutes for the circuit and 6 minute intervals. The extra minute at each end also ensures the stagger as they pass 12.

This leaves me with 16 trains. With hindsight when you stop over thinking the problem and try to write the problem in plainer English it seems more obvious, so it busts remains Wolfgang that should point out why this one is still not right!

• 0

### #52 wolfgang

wolfgang

Senior Member

• Members
• 783 posts
• Gender:Male

Posted 03 October 2011 - 06:46 PM

Each train moves in one minute intrval,that means:
stays one minute in each station.
The time needed between each two stations is one minute.
All trains move at the same time(all together,as if they are chained ).
The gape between them will stay fix.
At stations 1 and 24 it stays one minute,make an (one minute curve)reaching the same station,but at opposit direction.
If the first train was at station Number 1...so the second train should be at station Number 7(6min. interval)and so on.
The total number of the trains should be...8...
Thanks

Edited by wolfgang, 03 October 2011 - 06:48 PM.

• 0

### #53 Trainspotterx

Trainspotterx

Newbie

• Members
• 6 posts

Posted 03 October 2011 - 08:52 PM

Sorry can you explain how train at 1 gets to 7 in 6 minutes if it takes 1 minute between stations and stops for 1 minute at each. By my workings that must be 6 minutes moving and 6 minutes stationery which is 12 not 6!
• 0

### #54 wolfgang

wolfgang

Senior Member

• Members
• 783 posts
• Gender:Male

Posted 05 October 2011 - 09:02 PM

Let the start position to be like this:
from left to right, a train in station 1, 7,13,19
from right to left, a train in station 24,18,12,and 6
I am at station number 12, there is a train which will stay one minute then will move to the right.
as it moves,all the trains will move at the same time,like this:
from left to right,2,8,14,20
from right to left,23,17,11,5
after another movement:
3,9,15,21
22,16,10,4
and so on...after 4 minutes,the train that was at 7 will reach 12 from left side,the next train which was at 18 will reach 12 from the right side( after 5 min.).
• 0

### #55 thoughtfulfellow

thoughtfulfellow

• Members
• 218 posts

Posted 06 October 2011 - 04:47 AM

Let the start position to be like this:
from left to right, a train in station 1, 7,13,19
from right to left, a train in station 24,18,12,and 6
I am at station number 12, there is a train which will stay one minute then will move to the right.
as it moves,all the trains will move at the same time,like this:
from left to right,2,8,14,20
from right to left,23,17,11,5
after another movement:
3,9,15,21
22,16,10,4
and so on...after 4 minutes,the train that was at 7 will reach 12 from left side,the next train which was at 18 will reach 12 from the right side( after 5 min.).

You stated in post #24 that the time between 2 stations is 1 minute and yet claim that a train and also stated that time in each station is 1 minute. This would mean that the train that just arrived at 7, must stay 1 minute and spend 1 minute moving before reaching station 8. Continuing this thought means that the train at seven cannot reach 12 in less than 10 minutes because there are 5, gaps between stations, 1 minute each, and 5 stops of 1 minute at stations 7,8,9,10 & 11. I agree with Trainspotterx that you have a major problem with your solution of 8 trains.
• 0

### #56 wolfgang

wolfgang

Senior Member

• Members
• 783 posts
• Gender:Male

Posted 06 October 2011 - 07:13 PM

Yes...you are right..
• 0

#### 0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users