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?
120 m
240 m
300 m
None of these
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 12 of 28.

Shiji said:   1 decade ago
Why don`t we take the length of the train=15*36.

Surender Kashyap said:   1 decade ago
L/20 = (L+P)/36 = 54*5/18
using compenondo and dividendo means (L+P)-L/36-20
P/16 = 15
SO, P = 15*16
P = 240

Priyanka said:   1 decade ago
Train passes in 36 secs, man standing in 20 secs.
therefor, 36-20= 16 secs.
now, speed = 54 km/hr.
= {54 X 5/18} = 15 m/sec.
here, length = speed X time
= 15 X 16
= 240 m. ans

Guru said:   1 decade ago
The time taken by train to cross platform is=36-20=16sec.

Speed of train=54*(5/18)m/s.

Distance(length)=speed*time.

=54*(5/18)*16.

=240m.

Kabita said:   1 decade ago
Train passes in 36 secs, man standing in 20 secs.

Therefor, 36-20= 16 secs.

Now, speed = 54 km/hr.

= {54 X 5/18} = 15 m/sec.

Here, length = speed X time

= 15 X 16
= 240 m. ans

Mamtha said:   1 decade ago
The train pass the man 20sec, and the train pass a station 36sec.

So,36-20=16sec

Then we know that speed of the train of the train is 54km/hr.
=15m/sec

Therefore, 16*15=240m. Answer.

Muthu said:   1 decade ago
Train crossing station platform in 36 sec with speed of 54km/hr. Question asked what is the length of platform?

54 x 1000 /3600 = 15m/sec train travel distance.

So for 36 sec train is crossing the platform.

Total length of the platform is 36 x 15 = 540mts.

If question asked what is the length of train then we have to calculate 20 sec X 15 m /sec = 300 mts.

If asked what is the balance length of platform from man standing place, then (36-20= 16) 16 x 15 =240mts.

I hope my view is correct.

M.Ramya Devi said:   1 decade ago
Speed of the train=54km/hr.

Speed=54*5/18=15.

Train passes a station platform:Length=speed*time.

=15*36=540.

Train passes the man standing on the platform:Length=speed*time.

=15*20=300.

Length of the platform=540-300=240m.

Sangram said:   1 decade ago
In simple process,

Bs-------------------m------------Be

A--------20S---------B------16S---C

l---------------36s---------------l

If man was reference point then T.P=36-20=16s.
We know length=speed*time.
Then lenth of train=(54*5/18)*16=15m/s.*16s.=240m.

Answer=240m.

Shantanu said:   1 decade ago
Why x and 300m are added?


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