Aptitude - Problems on Trains - Discussion
Discussion Forum : Problems on Trains - General Questions (Q.No. 2)
2.
A train 125 m long passes a man, running at 5 km/hr in the same direction in which the train is going, in 10 seconds. The speed of the train is:
Answer: Option
Explanation:
| Speed of the train relative to man = |  |
125 |  m/sec |
| 10 |
| = | |
25 | m/sec. |
| 2 |
| = | |
25 | x | 18 | km/hr |
| 2 | 5 |
= 45 km/hr.
Let the speed of the train be x km/hr. Then, relative speed = (x - 5) km/hr.
x - 5 = 45 
x = 50 km/hr.
Discussion:
475 comments Page 24 of 48.
Sahil said:
9 years ago
Nice answer with explanation. It is very easy to understand.
Ankur said:
9 years ago
A train speeds past a pole in 15 seconds and a platform 100 m long in 25 seconds. Its length is:
Kindly solve it with full description.
Kindly solve it with full description.
Priyan singh said:
9 years ago
How can be its 50 ?
It's 45 km/hr.
If we put answer 45 km as speed of train.
Time = 125/45*5/18 = 10 m/s.
But if we 50 we can't get its time. 10 m/s.
Explain someone ?
It's 45 km/hr.
If we put answer 45 km as speed of train.
Time = 125/45*5/18 = 10 m/s.
But if we 50 we can't get its time. 10 m/s.
Explain someone ?
Pattinson said:
9 years ago
18/5 is to convert seconds to hours.
Vaitheesh kumar said:
9 years ago
Guys I have one doubt for finding out the relative speed we should need to subtract but here it's divided please explain me how?
Seena said:
10 years ago
Can someone please tell me? When we make the use of relative speed?
Kamal said:
10 years ago
Options only in km/hr.
Nagamani said:
10 years ago
In the given question 5 km\hr. So why you are calculated only km per hour?
Baji said:
10 years ago
Here the time 10 seconds is the time taken by the train to cross it's one length and the person running distance in 10 seconds.
So the travelled distance of the person in 10 seconds is = 5 km/hr*5/18*10 = 13.8888 mts.
And the train distance is 125 mts.
The total distance is = 138.88888.
So the finally the velocity of train is 138.8888/10.
= 13.8888888 mts/sec.
= 13.888888*18/5.
= 50 km/hr.
So the travelled distance of the person in 10 seconds is = 5 km/hr*5/18*10 = 13.8888 mts.
And the train distance is 125 mts.
The total distance is = 138.88888.
So the finally the velocity of train is 138.8888/10.
= 13.8888888 mts/sec.
= 13.888888*18/5.
= 50 km/hr.
Priya said:
10 years ago
To convert kilo meter/hour to meter/sec we consider 5/18.
To convert meter/sec to kilometer/hour we consider 18/5.
To convert meter/sec to kilometer/hour we consider 18/5.
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