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 19 of 48.
Basava g said:
8 years ago
First, we find total length to across moving man=125+((5*10^3)÷(3600))*10.
= 125+13.888.
= 138.88m.
The speed of train = total/time.
= 138/10,
= 13.88m/s.
This one convert into km/hrs.
= 13.88 * 3600,
= 50km/hrs.
= 125+13.888.
= 138.88m.
The speed of train = total/time.
= 138/10,
= 13.88m/s.
This one convert into km/hrs.
= 13.88 * 3600,
= 50km/hrs.
Sunil said:
8 years ago
Thank you all for the given explanations.
Shailesh Hiremath said:
8 years ago
So, kilometre & minutes will be calculated as 1 km=1000 mtrs and 60 minutes =3600 seconds.
If you divide 3600/1000 = 5/18.
If you divide 3600/1000 = 5/18.
Ganga said:
8 years ago
Why we subtract (x-5)?
Venkatesh said:
8 years ago
Thank you @Nagapriya.
Priyanka said:
8 years ago
Why we consider v=5 to subtract u - v?
Nishant said:
8 years ago
But it should have been given that we have to find the relative velocity of the man. So, 45km/hr should be the right answer.
Ajay said:
8 years ago
As per my calculation, 50 km/hr is the right answer.
Sushanth ratan said:
8 years ago
@Jothi.
-5 if it goes on the other side it becomes plus (+).
-5 if it goes on the other side it becomes plus (+).
Vinutha said:
8 years ago
Can anyone explain, how we will get to know that, the given length and time is for relative speed, and why can't it be related to speed of train?
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