Aptitude - Problems on Trains - Discussion
Discussion Forum : Problems on Trains - General Questions (Q.No. 25)
25.
A train 108 m long moving at a speed of 50 km/hr crosses a train 112 m long coming from opposite direction in 6 seconds. The speed of the second train is:
Answer: Option
Explanation:
Let the speed of the second train be x km/hr.
| Relative speed | = (x + 50) km/hr | |||||||
|
||||||||
|
![]](/_files/images/aptitude/1-sym-cbracket-h1.gif)
Distance covered = (108 + 112) = 220 m.
 |
220 | = 6 | ||
|
250 + 5x = 660
x = 82 km/hr.
Discussion:
77 comments Page 6 of 8.
Soumitra Das said:
9 years ago
Sorry I make a mistake in my last comment.
D = 108 + 112 = 120.
Converting the speed of 1st Train = 50x 5/18 m/s.
Let the speed of 2nd Train= V m/s.
We get,
220/ (50x 5/18) + V = 6 sec.
=> 220= 6x(250+18V)/18,
=> 220=(250+18V)/3,
=>660= 250+18V,
=>18V=410,
=> V= 410/18 m/s.
Converting the speed of the second Train we Get,
=> (410/18) x (18/5).
=> 82 Kmph.
This is the right answer
D = 108 + 112 = 120.
Converting the speed of 1st Train = 50x 5/18 m/s.
Let the speed of 2nd Train= V m/s.
We get,
220/ (50x 5/18) + V = 6 sec.
=> 220= 6x(250+18V)/18,
=> 220=(250+18V)/3,
=>660= 250+18V,
=>18V=410,
=> V= 410/18 m/s.
Converting the speed of the second Train we Get,
=> (410/18) x (18/5).
=> 82 Kmph.
This is the right answer
Ashwin kumar said:
9 years ago
@Ashok.
How you get 220/250 + 5x/18?
How you get 220/250 + 5x/18?
Sriram said:
8 years ago
We have got v (kmph) if it had been v * 5/18 then we would have gotten speed in m/s.
Gangani said:
7 years ago
First take 220/6=36.66 m/s.
Now convert into km/h so 132km/h.
and minus 50km/h from 132 - 50 = 82km/h.
Thanks.
Now convert into km/h so 132km/h.
and minus 50km/h from 132 - 50 = 82km/h.
Thanks.
Nileshshelar said:
7 years ago
(Total distance covered) ÷ (net speed) = time.
Mtrs/(mtr/sec) = sec.
220/(50+x) * 5/18=6,
So x=82.
But the unit is now mtr/sec because all we have converted into mtrs and seconds.
Mtrs/(mtr/sec) = sec.
220/(50+x) * 5/18=6,
So x=82.
But the unit is now mtr/sec because all we have converted into mtrs and seconds.
Gopal sunar said:
7 years ago
Thank you @Soumitra Das.
Nagesh said:
6 years ago
Thank you @Das.
Arkadev said:
6 years ago
Relative speed =220/6 * 18/5=132.
Second trains speed =132-50 = 80.
Second trains speed =132-50 = 80.
Prity sahay said:
6 years ago
If everything is converted into m/s then the answer will also be 82m/s not 82 km/hr.
(1)
Prem said:
6 years ago
I agree with you. @Prity.
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