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:
107 comments Page 6 of 11.
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:
1 decade 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:
1 decade 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:
1 decade ago
How 5/18 will came? Please clarify.
Suriya said:
1 decade 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:
1 decade 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:
10 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:
10 years ago
It's better to use shortcut method.
t = a + b /u - v.
t = a + b /u - v.
Naveen said:
10 years ago
@Sailesh, What you said is correct.
Ayush Chawla said:
10 years ago
Could the answer be wrong? Because, according to answer jogger is idle, as the distance covered by the jogger is not considered in the total answer? According to me, 48sec should be the right answer.
Could anyone give it a thought? That total distance should be 240 + 120 + T * 9 * (5/18) , supposing x is a distance moved by a jogger. Therefore x = T * (9 * 5/18).
Then the answer is 48, which is not mentioned in options.
Could anyone give it a thought? That total distance should be 240 + 120 + T * 9 * (5/18) , supposing x is a distance moved by a jogger. Therefore x = T * (9 * 5/18).
Then the answer is 48, which is not mentioned in options.
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