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:
282 comments Page 24 of 29.
Prajeesh said:
8 years ago
Speed conversion, 54*(5/18)= 15 m/s.
Length of train =15*20= 300m.
Formula:
The length of train= [length of platform/diffrence in time ]*time taken to cross stationary pole or man.
300=[x/36-20]20,
x=1200/5,
x =240m.
Length of train =15*20= 300m.
Formula:
The length of train= [length of platform/diffrence in time ]*time taken to cross stationary pole or man.
300=[x/36-20]20,
x=1200/5,
x =240m.
Rakshith said:
8 years ago
Can anybody explain me why are we taking 36-20, and Why 540-300?
Please explain this step.
Please explain this step.
Mounika said:
8 years ago
36 sec is the length of the train and platform. 20 seconds is the length of the train.
So, the length of the platform is 36-20=16 sec.
54*5/18 = 15m/sec is the speed of the train.
The length of the platform = 15*16 = 240.
So, the length of the platform is 36-20=16 sec.
54*5/18 = 15m/sec is the speed of the train.
The length of the platform = 15*16 = 240.
Ani said:
8 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:
8 years ago
Answer will be 240mt but the length of the train is more than the platform.
Rajesh said:
8 years ago
54 * (5/18) * (36-20)=240 is the correct method I think.
Mounika said:
8 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:
8 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:
8 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:
8 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.
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