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.
Priya said:
10 years ago
To convert kilo meter/hour to meter/sec we consider 5/18.
To convert meter/sec to kilometer/hour we consider 18/5.
To convert meter/sec to kilometer/hour we consider 18/5.
Raja said:
1 decade ago
Thank you friends I understood well never before.
Every one has given their own ideology with respect to problem.
Every one has given their own ideology with respect to problem.
Rohit said:
7 years ago
Whenever we have to convert seconds or minutes to an hour then multiply by 18/5 and if to do vice versa then 5/18.
Dhivya said:
7 years ago
L(train) = (speed of train-speed of object) * time.
125m = (St-5)km/hr * 10s,
112.5 * 18/5 = st - 5,
St = 50km/hr.
125m = (St-5)km/hr * 10s,
112.5 * 18/5 = st - 5,
St = 50km/hr.
Narendran Sainathan said:
7 years ago
18/5 is to convert meter per second to kilo meter per hour. Or you can also use 3600 (seconds)/1000 (kilometre).
Umair chudhary said:
1 decade 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.
Jasper said:
1 decade ago
How it is saying that relative speed of the train is 45?
Its only the speed of the train, can anyone tell me?
Its only the speed of the train, can anyone tell me?
Abid said:
1 decade ago
How to calculate what Km/Hr is train running if its length is 130 m and cross it own start point in 15 seconds?
Kumud Singh said:
7 years ago
@Ladura.
Distance covered by the man in 10 sec,
Speed = 5*5/18 = 25/18 m/sec,
Distance = 25/18*10 = 125/19 m.
Distance covered by the man in 10 sec,
Speed = 5*5/18 = 25/18 m/sec,
Distance = 25/18*10 = 125/19 m.
SURESHBABU KASTURI said:
1 decade ago
If two things are at same speed in same direction.
We subtract that,
So right 125-5=120.
Wrong is 125+5=130.
We subtract that,
So right 125-5=120.
Wrong is 125+5=130.
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