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 20 of 28.
Ani said:
7 years ago
Net time = 36-20 = 16,
So length of platform is =time * speed,
That is=16x15=240 MTR.
So length of platform is =time * speed,
That is=16x15=240 MTR.
Bhuwan Ranjan said:
7 years ago
Answer will be 240mt but the length of the train is more than the platform.
Rajesh said:
7 years ago
54 * (5/18) * (36-20)=240 is the correct method I think.
Mounika said:
7 years ago
First we convert to m/s.
54 * (5/18)=15m/s.
We know that length=speed * time.
=15 * (net time),
=15 * (36-20).
=15 * 16=240,
54 * (5/18)=15m/s.
We know that length=speed * time.
=15 * (net time),
=15 * (36-20).
=15 * 16=240,
Guravareddy said:
7 years ago
Given data is U is 36 sec V 20 secc speed is 54 km/h.
Convert the speed from km/h to m/s,
54*5/18 = 270/18 = 15m/sec,
relative speed of train in same direction ( U - V),
= 36 - 20 = 16.
now,
speed = dist/time ( s = d/t).
here we find the dist.
so,
D=S*T.
Now we have speed & time.
D=15*16 = 240m.
Convert the speed from km/h to m/s,
54*5/18 = 270/18 = 15m/sec,
relative speed of train in same direction ( U - V),
= 36 - 20 = 16.
now,
speed = dist/time ( s = d/t).
here we find the dist.
so,
D=S*T.
Now we have speed & time.
D=15*16 = 240m.
Agnel said:
7 years ago
Speed=54*5÷18=15.
:.15*20=300,
15*36=540,
--------------------
240.
Another option;
Speed 15.
36-20=16,
.:15*16=240.
:.15*20=300,
15*36=540,
--------------------
240.
Another option;
Speed 15.
36-20=16,
.:15*16=240.
Krishna said:
7 years ago
Here, the length of the train is more than the length of the platform, how can a train be fit on that platform?
Platform length is 240m and Train length is 300m. Please explain me about it.
Platform length is 240m and Train length is 300m. Please explain me about it.
RAMKUMAR said:
7 years ago
Speed=54*5 ÷ 18=15.
:.15*20=300,
15*36=540,
--------------------
240.
Another option;
Speed 15.
36-20=16,
Therefore, 15 * 16 = 240.
:.15*20=300,
15*36=540,
--------------------
240.
Another option;
Speed 15.
36-20=16,
Therefore, 15 * 16 = 240.
Aryan said:
7 years ago
Why did they take 20 instead of 36?
Roshan said:
7 years ago
Sol: speed of train in m/sec = 54*5/18.
=15 m/sec.
The total Distance of both = speed * time.
Platform and train =15 * 36 m
= 540m
And the Length of train = 20 * 15 m.
= 300m.
Plateform=(total distance - length of the train).
= (540 - 300) m,
= 240 m.
=15 m/sec.
The total Distance of both = speed * time.
Platform and train =15 * 36 m
= 540m
And the Length of train = 20 * 15 m.
= 300m.
Plateform=(total distance - length of the train).
= (540 - 300) m,
= 240 m.
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