Aptitude - Problems on Trains - Discussion
Discussion Forum : Problems on Trains - General Questions (Q.No. 10)
10.
A jogger running at 9 kmph alongside a railway track in 240 metres ahead of the engine of a 120 metres long train running at 45 kmph in the same direction. In how much time will the train pass the jogger?
Answer: Option
Explanation:
Speed of train relative to jogger = (45 - 9) km/hr = 36 km/hr.
| = |  |
36 x | 5 |  m/sec |
| 18 |
= 10 m/sec.
Distance to be covered = (240 + 120) m = 360 m.
 Time taken = |
|
360 | sec |
= 36 sec. |
| 10 |
Discussion:
106 comments Page 7 of 11.
Rohit basuri said:
1 decade ago
The jogger is also running. So, we also need to factor in the additional distance he covers.
If the time taken by train to cross the jogger is x.
(360+(9*5/18)*x)/10 = x.
x = 48 sec.
If the time taken by train to cross the jogger is x.
(360+(9*5/18)*x)/10 = x.
x = 48 sec.
Nilesh said:
1 decade ago
t = a+b/u-v.
Manojbatchu said:
1 decade ago
In how much time train crosses the jogger?
Then why they are adding the 240 m railway track length?
Jogger speed, train speed, train length enough. Please any one solve my doubt.
Then why they are adding the 240 m railway track length?
Jogger speed, train speed, train length enough. Please any one solve my doubt.
Rahul said:
10 years ago
The jogger is not idle eight, I think it is wrong because the jogger will run at a speed of 9 kmph during the time the train passes him so this distance should also be covered I solution but it is not the answer would be 48 sec.
Shubham singh said:
10 years ago
Suppose jogger is running at 18 kmph and rest things are same so according to the calculation as done in explanation time should be 360/(15/2) = 48 sec but in that time jogger have also run 48*5 = 240 m so yet 120 m ahead of train.
Prakash said:
10 years ago
How 5/18 will came? Please clarify.
Suriya said:
10 years ago
In any problem we will need to keep all the values in an uniform form, i.e. either all must be in m/sec or KM\hr.
In this problem they have converted from Km\Hr to m/sec. Therefore we multiply it my 1000/3600 (1 km = 1000 meters and 1 hour = 3600 seconds). When we cancel numerator and denominator we get, 5/18. This is how we get 5/18. Hope it helps.
In this problem they have converted from Km\Hr to m/sec. Therefore we multiply it my 1000/3600 (1 km = 1000 meters and 1 hour = 3600 seconds). When we cancel numerator and denominator we get, 5/18. This is how we get 5/18. Hope it helps.
Reddy said:
10 years ago
In this problem the question is how much time it take to cross the jogger why are you considering the plat form length?
Sailesh said:
9 years ago
They asked how much time the train pass jogger. Should the entire train pass the jogger (then distance=240 + 120) or should the engine only just pass the jogger (then distance =240).
Niveditha said:
9 years ago
It's better to use shortcut method.
t = a + b /u - v.
t = a + b /u - v.
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