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 4 of 48.
Owona Julius said:
2 years ago
How - 5 came? Please explain this step.
(17)
Shanthi said:
2 years ago
How this 18/5 come? please explain to me.
(17)
Sayak Chakraborty said:
2 years ago
How 18/5 came after 25/2? Please answer.
(16)
Bandi Pravalika said:
1 year ago
18/5 is the direct formula to convert the m/seconds to km/hr.
In this given problem, we can convert the m/sec to km/hr so we use 18/5.
In this given problem, we can convert the m/sec to km/hr so we use 18/5.
(14)
G Sekhar said:
10 months ago
This is the concept of reference of frame.
Train speed is (x)
Let's say A person in a train says that a man(outside of the train(or) beside of train running at a speed of 5 km/ hr) running slow as (x-5)km/hr.
This means if the train speed is 20 km/hr. Then the man's relative speed is as slow as 15 km/hr when compared to train speed.
This relation is mentioned in the mathematical formula as( x-5)km/hr or ( example:20-5 km/hr).
So, the relative speed is;
X - 5 = (120/10)*(18/5)
So x = 50 km/ hr.
*18/5 is used to convert m/s into km/ hr.
Train speed is (x)
Let's say A person in a train says that a man(outside of the train(or) beside of train running at a speed of 5 km/ hr) running slow as (x-5)km/hr.
This means if the train speed is 20 km/hr. Then the man's relative speed is as slow as 15 km/hr when compared to train speed.
This relation is mentioned in the mathematical formula as( x-5)km/hr or ( example:20-5 km/hr).
So, the relative speed is;
X - 5 = (120/10)*(18/5)
So x = 50 km/ hr.
*18/5 is used to convert m/s into km/ hr.
(14)
Webisa Ibrahim said:
9 months ago
I am not getting this. Anyone, help me to understand this.
(14)
Naveen reddy said:
2 months ago
125/10 = 12.5,
12.5 * 3.6 = 45,
45 + 5 = 50.
12.5 * 3.6 = 45,
45 + 5 = 50.
(13)
Fizza akhtar said:
1 year ago
Suppose we have to convert km/hour into m/s.
km/hour = 1000m/hour
i hour = 3600s
km/s = 1000m/3600s = 5/18.
Just reverse it, m/s into km/hour = 18/5, it's an easy way.
km/hour = 1000m/hour
i hour = 3600s
km/s = 1000m/3600s = 5/18.
Just reverse it, m/s into km/hour = 18/5, it's an easy way.
(11)
Apoorva Marathi said:
10 months ago
How it is 50? please explain to me.
(9)
Raghu k said:
4 years ago
It is simple guys.
If we observe hint, her there should be the relative speed because the train and are travelling in the same direction so we (train) -v (man) T =Distance.
(120/10) (18/5) =v (t) -5.
45+5=v (t).
50=v (t).
If we observe hint, her there should be the relative speed because the train and are travelling in the same direction so we (train) -v (man) T =Distance.
(120/10) (18/5) =v (t) -5.
45+5=v (t).
50=v (t).
(8)
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