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 | ![]() |
10 |
= | ![]() |
25 | ![]() |
2 |
= | ![]() |
25 | x | 18 | ![]() |
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 14 of 48.
Vikash gupta said:
7 years ago
Relative velocity is 125/10, how?
Bharat Gupta said:
7 years ago
Please explain the relative speed = (x - 5) km/hr.
Apoorva E said:
7 years ago
Whenever you convert speed from km/hr to m/sec you should multiply the speed by 5/18.
Vice versa when you convert m/sec to km/hr you should multiply the speed by 18/5.
Vice versa when you convert m/sec to km/hr you should multiply the speed by 18/5.
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.
Satya said:
7 years ago
Why is it divided by 18/5 and how it is? Please explain.
Shivam tomar said:
7 years ago
Speed of the train relative to man = 125/10 m/sec.
I am confused in this step, please clarify it.
I am confused in this step, please clarify it.
Koser said:
7 years ago
Why is it divided by 125/10?
Andrews Anbarasu said:
7 years ago
Your explanation is good @Ravi.
Thanks all.
Thanks all.
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.
Kumud Singh said:
7 years ago
1 km = 1000 meters.
1 hr = 3600 seconds.
1 km/hr = 1000/3600 m/s.
= 10/36 m/s.
= 5/18 m/s.
@Gilbert & Dk Singh.
Therefore 1 km/hr = 5/18 m/sec.
Similarly, the reciprocal of m/sec is used to calculate km/hr.
1 hr = 3600 seconds.
1 km/hr = 1000/3600 m/s.
= 10/36 m/s.
= 5/18 m/s.
@Gilbert & Dk Singh.
Therefore 1 km/hr = 5/18 m/sec.
Similarly, the reciprocal of m/sec is used to calculate km/hr.
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