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:
277 comments Page 26 of 28.
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.
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.
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.
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.
Omkar Nivalagi said:
6 years ago
Simply;
Find speed in m/sec
54*(5/18).
And the difference between two lengths from plat1 to plat2 i,e (36-20)=16 and this is to the time taken to cross length plat1 to plat2 in secs.
As we know s=d/t;
5/18*16=240; answer
Find speed in m/sec
54*(5/18).
And the difference between two lengths from plat1 to plat2 i,e (36-20)=16 and this is to the time taken to cross length plat1 to plat2 in secs.
As we know s=d/t;
5/18*16=240; answer
Ramu said:
6 years ago
Any one please explain me.
Shelke ganesh mariba said:
6 years ago
According to speed of trai = 15m/s.
And time = 36-20 = 16sec.
Therefore length of platform = 15x16 = 240m.
And time = 36-20 = 16sec.
Therefore length of platform = 15x16 = 240m.
Kartik said:
6 years ago
54*5/18 = 15m/sec.
36-20 = 16 seconds.
Distance = speed *time.
Distance = 15m/sec*16 seconds.
Distance = 240m.
36-20 = 16 seconds.
Distance = speed *time.
Distance = 15m/sec*16 seconds.
Distance = 240m.
Raghul said:
6 years ago
There is no length for man hence,
L/15 = 20.
L= 300.
And platform has length hence,
L+B/15 =36.
300+B = 540.
B=240.
L/15 = 20.
L= 300.
And platform has length hence,
L+B/15 =36.
300+B = 540.
B=240.
Cnine said:
6 years ago
The second method is, Convert the speed in m/sec.
And man is standing in platform then the both given time is subtract to each other and the subtract answer is multiplied the speed.
And man is standing in platform then the both given time is subtract to each other and the subtract answer is multiplied the speed.
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