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 8 of 28.

Harsh said:   7 years ago
I think the answer should be 540.

Because, how can the length of the platform be less than the length of the trian?

Manisha dambe said:   7 years ago
Time to pass platform = 16s,
length of platform=t*s,
= 16*54*5/18=245.
The length of platform=245 m.

Shivam singh said:   7 years ago
Km/h to m/s.
So,
54kmph = 54*5/18 = 15m/s.

The Length of platform = speed * time difference (because 20 is referral point)
= 15 * (36 - 20) = 240m.

Kavya said:   7 years ago
Very good answer @Vetri.

Nisha said:   7 years ago
Thanks, @Vetri.

Er.Shubham said:   7 years ago
@Krishna,

Don't compare the Length of both.

Take only the starting and ending point.

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.

Aryan said:   7 years ago
Why did they take 20 instead of 36?

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.

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.


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