Aptitude - Problems on Trains - Discussion

Another method we do that problem.

Train reach time-man standing time = 36-20 = 16.

Length = 15*16 = 240m.

Friends, I did like this to get an answer. I think it will help you.

Speed of train 54 km/hr 54*5/18 = 15 m/sec

Platform passed in 36 seconds

man stands on platform about 20 seconds
So, 36 - 20 = 16

Length of platform = Speed of train * time taken to pass(leftover seconds from man stood)
Distance = 15*16.
= 240.

Here, platform length is asked then only 36 sec would be considering I think. Because the man is standing on the platform then its passes time covered in 36 sec.

So please give me solution regarding this.

All of you have got answer rightly. According to my understanding, time spent by a train to cross a man is at the 20s. A man is standing at an extreme end of a train. Thus, a length of the train could be traded.

Friends, this method also can apply.

We know Time is taken by a train to cross a Standing man = (Length of the train) / (Speed of the train).

Thus, 20 = Length of the train/ (54 x 5/18).

So length of the train= 20 x 54 x 5/18 = 300 m.

Also, we know Time taken by a train to cross a Platform.

= (Length of the train+Length of the platform) / (Speed of the train).

I. E, 36= (300 + Length of the platform) / (54 x 5/18).

300+ So length of the platform = 36 x 54 x 5/18 = 540.

So, the length of the platform = 540 - 300 = 240 m.

Let me put it straight 300 is the length of the train. Then in the problem, it should be treated as 300 + 300 + length of the platform.

It should take the tip as the entry and tail as exit and by that time it would have covered 600 m.

Why have we divided by 36?

Hii guys, I think.

Length = speed * time.

We have to find platform length so we have taken the man standing on platform time.

Therefore, length = 15 * 20.

Hi, Friends,

Here given is that train takes 36 sec to cover a distance which is the length of the platform. Because here clearly given that. The train which is having speed 54km/hr takes time 36 sec to cover distance i.e the length of the platform. So I think there is no need to take into consideration the length of the train.

Easily way.

Train speed is 54 in KM/HR so KM/HR = 1000 M /3600 S = 10/36 = 5/18 * 54 train speed = 15 M/S.

Train crossed in 36 man in 20 so we can minus both so 36 - 20 = 16.
16 * 15 = 240.