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:
493 comments Page 10 of 50.
Umair chudhary said:
2 decades ago
If someone feel difficult to understand 5/18 i.e; m/s
To convert kmph to mps 1000/60*60 m/s
It is same thing.
To convert kmph to mps 1000/60*60 m/s
It is same thing.
Sreenivas reddy said:
2 decades ago
Yeah superb.
Kamalakannan said:
2 decades ago
Answer = 45 km/hr is relative speed of the train.
Now, you calculate (u-v).
The Speed of the train 50 km/hr answer is correct.
Now, you calculate (u-v).
The Speed of the train 50 km/hr answer is correct.
Antony said:
2 decades ago
Please explain 18/5.
Sheela said:
2 decades ago
1km=1000m.
1hour=3600sec.
So to convert from km/hr to m/sec, we need to divide 3600/1000 i.e,.
1km/1hr=3600s/1000m which is equal to 18/5.
If it was asked to convert m/s to km/hr then it would be 1000m/3600s= 5/18
1hour=3600sec.
So to convert from km/hr to m/sec, we need to divide 3600/1000 i.e,.
1km/1hr=3600s/1000m which is equal to 18/5.
If it was asked to convert m/s to km/hr then it would be 1000m/3600s= 5/18
Saranya said:
2 decades ago
I could not understand this problem is there any way to understand this more easily.
Nagapriya said:
2 decades ago
Now I understand that,.
Distance = Speed*Time.
Time = Distance/Speed.
Speed= Distance/Time.
OK guys, very thanks to your teaching.
Distance = Speed*Time.
Time = Distance/Speed.
Speed= Distance/Time.
OK guys, very thanks to your teaching.
Amit said:
2 decades ago
Can any one tell me why we have mulipled 25/2 to 18/5..why it should not be multiplied by 5/18 and also how ?
x - 5 = 45 ....as I understand it should be 40 km/hr
x = 50 km/hr. Because x=45.
45-5=40....hence anyone pls clarify.
x - 5 = 45 ....as I understand it should be 40 km/hr
x = 50 km/hr. Because x=45.
45-5=40....hence anyone pls clarify.
Srikanth Mirdati said:
2 decades ago
Could anyone please tell me how we get to 25/2 by dividing 125/10. I want to know how the division of 125/10 is done to get 25/2 an answer would be appreciated greatly.
Shabana said:
2 decades ago
Hi, Really the explanation given by Dattatray & Rahul was superb. Thanks guys.
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