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:
476 comments Page 19 of 48.
SRIKANTH said:
9 years ago
Another method friends but bit lengthy.
D = S X T.
125 = (A - 25/18)10,
25 = (18A - 25)/9,
18A - 25 = 225,
18A = 250,
A = 250/18 X 18/5 = 50 KMPH.
D = S X T.
125 = (A - 25/18)10,
25 = (18A - 25)/9,
18A - 25 = 225,
18A = 250,
A = 250/18 X 18/5 = 50 KMPH.
Akeer said:
7 years ago
@Ganesh.
The Relative means related to speed. The two trains are in which direction moving based on that we have to take the speed to add or sub.
The Relative means related to speed. The two trains are in which direction moving based on that we have to take the speed to add or sub.
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?
Sarang said:
7 years ago
Distance=speed * time.
In same direction speed is added,
125=speed*10,
125/10= speed,
12.5 *18/5,
45 relative speed of train,
5 + 45 = 50.
In same direction speed is added,
125=speed*10,
125/10= speed,
12.5 *18/5,
45 relative speed of train,
5 + 45 = 50.
Sunil said:
1 decade ago
How/ why Let the speed of the train be x km/hr. Then, relative speed = (x - 5) km/hr.
Please any one explain me why let speed =(x-5)km hr.
Please any one explain me why let speed =(x-5)km hr.
Vinoda patil said:
2 years ago
To convert m/s to km/hr we use direct formula,
i.e 18/5.
Here,1km/hr = 5/18 m/sec.
To convert a given data from m/sec to km/hr we use 18/5.
i.e 18/5.
Here,1km/hr = 5/18 m/sec.
To convert a given data from m/sec to km/hr we use 18/5.
(27)
PRajashree said:
10 months ago
3600sec then, 1sec = 1/3600hr.
1km =1000m then, 1m = 1/1000km.
So,
km/hr to m/s is : 1/1000km bigger divided by 1/3600hr.
So, they put 18/5.
1km =1000m then, 1m = 1/1000km.
So,
km/hr to m/s is : 1/1000km bigger divided by 1/3600hr.
So, they put 18/5.
(19)
Arul said:
1 decade ago
Hey the quesion is about the speed of the train. jjust bcoz aman runs... will the speed of the train increase...? a little help here pls...
Sadhana said:
1 decade ago
Please explain the km/s. We should get the km/s is 5/18, but why we would get the 18/5. How is possible it is? Please explain this friends.
Imran said:
7 years ago
@Nivetha.
(x-5) is additional speed for overcrossing, the relative speed is 50-5=45. So here answer is 50 because (x-5) is crossing speed.
(x-5) is additional speed for overcrossing, the relative speed is 50-5=45. So here answer is 50 because (x-5) is crossing speed.
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