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 5 of 11.
Manish kumar meena said:
1 decade ago
How can the distance be 240 + 120. Until the train's engine covers 240m in that time the jogger will also move some distance ahead. So the total distance is not 240+120.
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.
Priyanka said:
2 decades ago
Can you explain me why in this question relative speed is subtaction of higher speed to lower while in same direction relative speed is addition of both object speed?
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.
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.
Profie said:
2 years ago
The total distance covered by the train will be 288m with its original speed. Thereafter relative velocity will take place. So, the actual answer is 35.04 sec
(3)
Gaurav choubey said:
1 decade ago
Step 1 find train speed in m/s 45*5/18=10m/sec.
Length og train=speed*time.
120=10*x=12 sec.
But 240 more to covered then
240+120=10*x.
x=36 answer.
Length og train=speed*time.
120=10*x=12 sec.
But 240 more to covered then
240+120=10*x.
x=36 answer.
Aditya bala said:
1 decade ago
We calculate relative speed for opposite and same direction if they travel in opposite direction we add them, in same direction we substract them.
Ram said:
1 decade ago
Answer is 48 sec as jogger also jogs 2.5x distance.
= 360+2.5x/x = 10.
= 360+2.5x = 10x.
= 360 = 7.5x.
= 48 = x.
Hence 48 sec is the answer.
= 360+2.5x/x = 10.
= 360+2.5x = 10x.
= 360 = 7.5x.
= 48 = x.
Hence 48 sec is the answer.
Maulik Dodia said:
1 decade ago
But I can not understand, that the tain have to pass the only 120m distance w.r.t the jogger. Not 240? Isn't it? Can anyone explain me that?
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