Aptitude - Problems on Trains - Discussion
Discussion Forum : Problems on Trains - General Questions (Q.No. 5)
5.
A train passes a station platform in 36 seconds and a man standing on the platform in 20 seconds. If the speed of the train is 54 km/hr, what is the length of the platform?
Answer: Option
Explanation:
| Speed = |  |
54 x | 5 |  m/sec = 15 m/sec. |
| 18 |
Length of the train = (15 x 20)m = 300 m.
Let the length of the platform be x metres.
| Then, | x + 300 | = 15 |
| 36 |
x + 300 = 540
x = 240 m.
Discussion:
276 comments Page 7 of 28.
Revanth said:
6 years ago
Given
t(p) =36s.
t(m)=20s.
Speed of the train = 54km/hr.
As we all know that speed = distance/ time.
Now, we have to convert the speed in m/s.
So, 54*5/18=15 m/s.
S=d/t => l/t.
L(t)= s*t => 15 m/s * 20s = 300m,
Now l(t)+l(b)= 15 m/s * 36s,
300m + l(b) = 540m.
L(b) = 540-300,
L(b)= 260 m.
t(p) =36s.
t(m)=20s.
Speed of the train = 54km/hr.
As we all know that speed = distance/ time.
Now, we have to convert the speed in m/s.
So, 54*5/18=15 m/s.
S=d/t => l/t.
L(t)= s*t => 15 m/s * 20s = 300m,
Now l(t)+l(b)= 15 m/s * 36s,
300m + l(b) = 540m.
L(b) = 540-300,
L(b)= 260 m.
Vishnu said:
6 years ago
The train has to pass the platform.
It means the tail end of the train has to pass the end of the platform. So the distance of the platform + length of the train has to be considered as distance travelled by train for 36 seconds.
It means the tail end of the train has to pass the end of the platform. So the distance of the platform + length of the train has to be considered as distance travelled by train for 36 seconds.
Vrunda savaliya said:
6 years ago
First substract time =36-20 = 16.
Then,
16 * 54 * 5/18.
Length = 240m.
Then,
16 * 54 * 5/18.
Length = 240m.
Suraj said:
6 years ago
Here, it is solved by taking 15*20 but why?
20 is speed of man not a train. We are taking into account that speed of train. If we take the speed of train then answer will becomes zero.
20 is speed of man not a train. We are taking into account that speed of train. If we take the speed of train then answer will becomes zero.
Abhi singh said:
6 years ago
54 * 5/18 = 15.
You have values than 36-20 after you get=16, now
15*16 = 240m/s,
And this is easily finding your ans = 240m/s.
You have values than 36-20 after you get=16, now
15*16 = 240m/s,
And this is easily finding your ans = 240m/s.
Ramya said:
6 years ago
Please explain, how come 15*20?
Length of the train means we have to do 15*36, right?
Length of the train means we have to do 15*36, right?
Remee Rahul said:
6 years ago
Does the man standing on the starting/intial point of the platform?
Jesudas said:
7 years ago
@Sagar Dombale.
It's the conversion of km/h to m/s.
It's the conversion of km/h to m/s.
Sagar Dombale said:
7 years ago
What is 5/18? Please explain me.
Somnath sen said:
7 years ago
Anyone Please explain it for me.
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