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 3 of 11.
Rohan said:
7 years ago
Why is the total distance taken as 240+120?
Karthik said:
7 years ago
Why relative speed covered entire distance. I suspect that when train engine enter to jogger after that we should consider relative speed?
Please explain anyone.
Please explain anyone.
Kavya said:
7 years ago
Why didn't we use relative speed formula here instead why we did use the speed of train relative to jogger?
Please explain me.
Please explain me.
MasterMind said:
7 years ago
Same direction,
d1+d2=240+120,
d=360,
speed :(same direction,)
s1-s2=45-9=36kmph.
36*5/18=10m/s,
therefore,
assume time=x,
d=speed*time ,
360=10*(x).
36 = x.
d1+d2=240+120,
d=360,
speed :(same direction,)
s1-s2=45-9=36kmph.
36*5/18=10m/s,
therefore,
assume time=x,
d=speed*time ,
360=10*(x).
36 = x.
Jime said:
7 years ago
Why do we add the distance with direction?
Afreen said:
7 years ago
For same direction,
t=l1+l2/s1-s2.
t=l1+l2/s1-s2.
(1)
Vivek Manve said:
7 years ago
Jogger is also running. So he will cover some distance, that should be taken in calculation right?
Shubhangi nema said:
7 years ago
A jogger is a point object so why we consider the platform length?
Pratik said:
8 years ago
@All.
I have a doubt. The jogger was not static. This means he/she must have covered some distance before the train crosses, all the solutions have not included this issue. Should I neglect that distance or is there anything I am missing.
To me, total distance = train length+ 240 metre+ the joggers covered path.
Is that correct or not. If not please help.
I have a doubt. The jogger was not static. This means he/she must have covered some distance before the train crosses, all the solutions have not included this issue. Should I neglect that distance or is there anything I am missing.
To me, total distance = train length+ 240 metre+ the joggers covered path.
Is that correct or not. If not please help.
Gokul said:
8 years ago
Here the equation is (l1+l2)/(v2+v1).
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers