Discussion topic: Puzzles & Brain Teasers : The Bird and the Train
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Page 1 of 1  From: syvum  Reply 1 of 4  Reply   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: diavan  Reply 2 of 4  Reply   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
DbDt
A MB
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: ralphheinrich  Reply 3 of 4  Reply   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: ralphheinrich  Reply 4 of 4  Reply   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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