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From: syvumReply 1 of 4Reply
Subject: Puzzles & Brain Teasers : The Bird and the Train
   Discuss this puzzle with other Syvum members in this forum.	If you have
   alternative solution procedures, or questions about this puzzles, feel free
   to post them here.

Posted at: Sun Jul 13 03:39:21 2003 (GMT)

From: diavanReply 2 of 4Reply
Subject: The Bird and the Train Ur solution is wrong!
   Hi,
   
   I am sorry but I am not convinced with your solution and I believe that it
   is wrong!
   
   Here is my solution!
   
   Speed of bird  x time (t1) = distance covered by bird  Db
   Speed of train x time (t2) = distance covered by train  Dt
   
   Db + Dt = 84
   
   |-------------------84-----------------------|
   |----------Db------------|-------Dt----------|
   A----------------------- M-------------------B
   
   
   Speed of bird  x time (t1) = distance covered by bird  Db
   80 x t1 = Db
   
   Speed of train x time (t2) = distance covered by train  Dt
   60 x t2 = Dt
   
   As Db+Dt = 84 so
   
   80 x t1 + 60 x t2 = 84
   
   t1 = t2 = t
   
   The distances Db and Dt are covered in the same time to arrive at meeting
   point M.
   
   80 x t + 60 x t = 84
   t = 0.6 h
   
   Db = 80 x 0.6
   Db = 48 km
   Total distance = 2 x Db = 96 Km !

Posted at: Fri Nov 5 12:32:48 2004 (GMT)

From: ralphheinrichReply 3 of 4Reply
Subject: bird and train
   What ever your proposed solution is, I think the correct one is as follows:
   
   If the train travels at 60 miles/hour, i.e. a mile a minute, it takes 78
   minutes to reach Barcena, which is 78 miles from Atena. According to the
   puzzle, the bird will be flying back and forth until the train reaches
   Barcena, i.e. the bird will be flying for 78 minutes. For the solution, it
   does not matter whether the bird flies back and forth between the train and
   Barcena, or whether it flies in circles over Barcena, or whether it flies in
   the opposite direction from Atena for 36 minutes and then returns, or
   whatever. The distance covered depends only on the fact that it flies for 78
   minutes at a speed of 70 miles/hour. 70 miles/hour is 7/6 miles a minute,
   hence the bird will travel 7/6 x 78 or 7 x 13 = 81 miles.
   
   If the bird's speed is 60 miles/hour, i.e. a mile a minute, then it will
   cover a distance equivalent to the time the train takes to reach Barcena. If
   the train travels at 70 miles/hour, it will take 6/7 of a minute to travel
   one mile, and hence 6/7 x 78 minutes to reach Barcena. Hence the bird will
   trave 6/7 x 78 miles in that case, which is 66.85714 miles.

Posted at: Mon Jul 27 13:49:11 2009 (GMT)

From: ralphheinrichReply 4 of 4Reply
Subject:
   Man, you guys really need to correct your software! I just did the puzzle
   again with different numbers (distance Atena - Barcena 90 miles, train/ bird
   travel at 90/60 miles, respectively), and your software confirmed 135 as the
   correct answer in the 1st case (train travel at 60 miles/hour, hence needs
   1.5 hours, bird travelling at 90 miles/hour covers 90x 1.5 = 135 miles in
   that hour), but again rejected the correct answer in the 2nd case (train
   travels at 90 miles/hour, hence reaches Barcena in one hour; bird travelling
   at 60 miles/hour therefore travels 60 miles in that hour).

Posted at: Mon Jul 27 13:56:11 2009 (GMT)

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