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 23 of 48.
Srinivas Rao said:
1 decade ago
If both things are in the same direction, then we have to do subtraction right but why we have to do it.
Sankar said:
1 decade ago
Man has traveled 13.8 m in 10 sec.
i.e 5km/hr = 1.38m/s.
1.38*10s=13.8m he has traveled in 10 sec.
So 125m train has passed 13.8m in 10 sec.
So speed of the train is 13.8m/s i.e 49.68km/hr = 50 km/hr.
i.e 5km/hr = 1.38m/s.
1.38*10s=13.8m he has traveled in 10 sec.
So 125m train has passed 13.8m in 10 sec.
So speed of the train is 13.8m/s i.e 49.68km/hr = 50 km/hr.
PRIYANKA SHARMA said:
1 decade ago
Hello friends,
If you want to convert m/s into km/hr then multiply with 18/5.
For example: 5 m/s = 5m/s*18/5 = 18km/hr.
If you want to convert km/hr into m/s then multiply with 5/18.
For example: 108 km/hr = 108km/hr*5/18 = 30m/s.
If you want to convert m/s into km/hr then multiply with 18/5.
For example: 5 m/s = 5m/s*18/5 = 18km/hr.
If you want to convert km/hr into m/s then multiply with 5/18.
For example: 108 km/hr = 108km/hr*5/18 = 30m/s.
Satish said:
1 decade ago
What is the need of taking 15/10 and explain how it came?
Akshay said:
1 decade ago
Why should multiply 18/5?
Deepak meena said:
1 decade ago
It's simple way.
We know that the speed of train is 125m/10s.
Then 125/10 = 25/2.
This is the speed of train in 1 second.
Now speed in 1 hr = 25/2*3600 = 45.
And men is going in 5km/1hr so speed of train is 50km/hr.
We know that the speed of train is 125m/10s.
Then 125/10 = 25/2.
This is the speed of train in 1 second.
Now speed in 1 hr = 25/2*3600 = 45.
And men is going in 5km/1hr so speed of train is 50km/hr.
Krish said:
1 decade ago
How to be solve this 25/2*18/5 = 45?
AAKASH said:
1 decade ago
125m/10s*18/5=45.
The man running in opposite direction at a speed of 5 km so 45+5=50.
The man running in opposite direction at a speed of 5 km so 45+5=50.
Givid said:
1 decade ago
I have a doubt on question. Whose speed is 5km/hr? either the man's or train's? please explain.
Ramkumar said:
1 decade ago
Why use 60*60/1000(18/5) I do not understand that?
Please explain.
Please explain.
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers