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 44 of 48.
Priyanka devi said:
4 years ago
@Rahul.
Great work, Thanks for explaining.
Great work, Thanks for explaining.
(7)
Iliyas said:
3 years ago
m/sec = [1/1000 km] / [1/3600 sec]
= [1/1000] *[3600/1],
= [3600/1000].
= [18/5]km/hr.
= [1/1000] *[3600/1],
= [3600/1000].
= [18/5]km/hr.
(28)
Osaji Jeff said:
3 years ago
Why was the formula reversed from 5/18 to 18/5? Please explain me.
(29)
Mohammed Asif said:
3 years ago
The speed of train is 45 km per hour
And relative speed is 50 km per hour.
But in the question only speed of train is asked not the relative speed.
So, please either change the question and mention relative speed or change the answer to option A 45 km per hour which is the speed of train.
And relative speed is 50 km per hour.
But in the question only speed of train is asked not the relative speed.
So, please either change the question and mention relative speed or change the answer to option A 45 km per hour which is the speed of train.
(37)
Rahul agrawal said:
2 years ago
125 m = 10sec
Than 60sec = 125 x 6 = 750m
1hour = 750 x 60 = 45000m (45km/hr) + 5km/hr = 50km/hr.
Than 60sec = 125 x 6 = 750m
1hour = 750 x 60 = 45000m (45km/hr) + 5km/hr = 50km/hr.
(60)
Jaimin Patel said:
2 years ago
Let X km/hr be the speed of the train.
Length = 125m = 0.125km.
Relative Speed= (X-5)km/hr (as train and man moving in the same direction hence it is subtracted).
0125/(X-5) = 10/3600.
X = 50km/hr.
Length = 125m = 0.125km.
Relative Speed= (X-5)km/hr (as train and man moving in the same direction hence it is subtracted).
0125/(X-5) = 10/3600.
X = 50km/hr.
(26)
Ashik Multani said:
2 years ago
Given
Length of train = 125m
Speed of man = 5km/hr = 5 * 5/18 = 25/18
Time = 10sec.
Speed = distance/time
Man running in the same direction so;
Let theh speed of the train is x.
speed = x - 25/18;
then by formula;
x - 25/18 = 125/10
x = 125/10 + 25 /18
x = 250/18 sec/m
Then;
convert into km/hr.
speed = 250/18 * 18/5.
speed = 50 => ans.
Length of train = 125m
Speed of man = 5km/hr = 5 * 5/18 = 25/18
Time = 10sec.
Speed = distance/time
Man running in the same direction so;
Let theh speed of the train is x.
speed = x - 25/18;
then by formula;
x - 25/18 = 125/10
x = 125/10 + 25 /18
x = 250/18 sec/m
Then;
convert into km/hr.
speed = 250/18 * 18/5.
speed = 50 => ans.
(45)
Chinnupradhan said:
2 years ago
S = L/T.
S = 125/10
S = 25/2.
then,
M/sec to km/hr convert.
1km/hr = [1000m/3600sec] = 5/18m/sec,
m/sec = 18/5km/hr.
i.e
(25/2 * 18/5)km/hr,
45km/hr.
Therefore first train x-5 = 45.
X = 50 km/hr.
S = 125/10
S = 25/2.
then,
M/sec to km/hr convert.
1km/hr = [1000m/3600sec] = 5/18m/sec,
m/sec = 18/5km/hr.
i.e
(25/2 * 18/5)km/hr,
45km/hr.
Therefore first train x-5 = 45.
X = 50 km/hr.
(30)
Owona Julius said:
2 years ago
How - 5 came? Please explain this step.
(17)
Sourabh said:
2 years ago
Given data :
Length Of the Train 125 meters.
Speed of Man = 5 km/hr
Speed of train = ?
Time = 10 sec.
Distance = Time * Velocity (speed).
125 = 10 × v,
V = 125/10,
V = 25/2 M/sec Now Convert it into Km/hr,
V = 25/2 × 18/5,
V = 45 km/hr.
And given In The Question train And Man Is Traveling in Same Direction.
V = Speed of train - Speed Of Man.
45 = Speed of train - 5.
Speed of train = 45+5.
Speed of train = 50 km/hr.
Length Of the Train 125 meters.
Speed of Man = 5 km/hr
Speed of train = ?
Time = 10 sec.
Distance = Time * Velocity (speed).
125 = 10 × v,
V = 125/10,
V = 25/2 M/sec Now Convert it into Km/hr,
V = 25/2 × 18/5,
V = 45 km/hr.
And given In The Question train And Man Is Traveling in Same Direction.
V = Speed of train - Speed Of Man.
45 = Speed of train - 5.
Speed of train = 45+5.
Speed of train = 50 km/hr.
(179)
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