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 3 of 8.
Ravi tomar said:
6 years ago
220m=0.220km : 6 sec = 1/600 hr.
0.220/ (50+x) = 1/600
0.220x600 = (50+x) => 132 = 50+x
x = 132-50=82,
x=82 km/hr.
0.220/ (50+x) = 1/600
0.220x600 = (50+x) => 132 = 50+x
x = 132-50=82,
x=82 km/hr.
Ashwin kumar said:
9 years ago
@Ashok.
How you get 220/250 + 5x/18?
How you get 220/250 + 5x/18?
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
Soumitra Das said:
9 years ago
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=390,
=> V= 390/18 m/s.
Converting the speed of the second Train we Get
=> (390/18) x (18/5)
=> 78 Kmph.
This is the right answer
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=390,
=> V= 390/18 m/s.
Converting the speed of the second Train we Get
=> (390/18) x (18/5)
=> 78 Kmph.
This is the right answer
Amitesh said:
9 years ago
The solution is not clear for it. Can anybody solve it easily?
Amitesh said:
9 years ago
220/6 = 250 + 5x/18,
By solving it we get,
3960 = 1500 + 30x,
2460 = 3x,
So, x = 82.
By solving it we get,
3960 = 1500 + 30x,
2460 = 3x,
So, x = 82.
Apoorv said:
9 years ago
Sir, if the train is moving in an opposite direction the total distance one has to cover is the larger length. So why have we added the two?
Ravi said:
9 years ago
Simple solution method:.
Length of train 1st is = 108m.
Speed of train 1st is = 50km/h => 50 * 5/18 == 125/9 m/sec.
Length of trian - 2nd is = 112m.
Now, let the speed of 2nd tarin is = x m/sec.
Relative speed =x + (125/9).
Relative distance = 108 + 112 = 220 m.
Time = 6 sec.
Now, s = d/t.
=> x + 125/9 = 220/6 (therefore 220/6= 110/3).
=> x = (110/3) - (125/9).
=> x = 205/9 m/sec (205/9) * (18/5).
x = 82 km/h answer.
Length of train 1st is = 108m.
Speed of train 1st is = 50km/h => 50 * 5/18 == 125/9 m/sec.
Length of trian - 2nd is = 112m.
Now, let the speed of 2nd tarin is = x m/sec.
Relative speed =x + (125/9).
Relative distance = 108 + 112 = 220 m.
Time = 6 sec.
Now, s = d/t.
=> x + 125/9 = 220/6 (therefore 220/6= 110/3).
=> x = (110/3) - (125/9).
=> x = 205/9 m/sec (205/9) * (18/5).
x = 82 km/h answer.
Azam Khan said:
9 years ago
How Comes 5 in answer? I can't Understand please explain this.
Gargi Banerjee said:
1 decade ago
Please give an appropriate answer with perticular reason, this is not clear to me.
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