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 8 of 11.
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.
Sandeep said:
10 years ago
Can anyone explain by using formula a + b / u - v?
Priya said:
9 years ago
What is the unit digit of 991^45? Can anyone tell me?
Raaj said:
9 years ago
If the direction of both things is in the same direction then the relative speed will be subtracted but in the case of opposite direction, relative speed will be added.
Shubh said:
9 years ago
What will be the shortcut method if trains are moving in opposite directions?
Shubham said:
9 years ago
as (a+b/u-v).
(45-9) * 5/18 = 10m/s.
(120 + 240/10) = 36s.
(45-9) * 5/18 = 10m/s.
(120 + 240/10) = 36s.
Raj vora said:
9 years ago
Can you please explain why we have to add 240 + 120?
Neerja said:
9 years ago
@Raj Vora.
The distance between the jogger and train is 240m so to first catch up to the jogger the train has to travel 240m. The length of the train is 120m so to completely pass the man and overtake him the train has to travel the length of the train, i.e. 120m.
Therefore total distance to be travelled by the train is 120m+240m=360m.
Hope this helped.
The distance between the jogger and train is 240m so to first catch up to the jogger the train has to travel 240m. The length of the train is 120m so to completely pass the man and overtake him the train has to travel the length of the train, i.e. 120m.
Therefore total distance to be travelled by the train is 120m+240m=360m.
Hope this helped.
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