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 9 of 28.
Manikandan said:
5 years ago
From the given data, we can consider the only man as a reference point to find the length of train. So let us consider man is standing at the beginning, so 15*20 will be enough to find the length of the train, Am I right?
Rahul Baranwal said:
9 years ago
I think there should be clarified in the question. That the man is exactly standing the place as the train is long.
Then only we can take the train length according to given solution.
Otherwise, the solution is wrong.
Then only we can take the train length according to given solution.
Otherwise, the solution is wrong.
Afroz khan said:
1 decade ago
Hello everyone.
Which is the right answer, I can understand the login given by you people, but the question raised by nick is absolutely correct. Can someone explain me in more detail so that I could clear my doubts.
Which is the right answer, I can understand the login given by you people, but the question raised by nick is absolutely correct. Can someone explain me in more detail so that I could clear my doubts.
Prajeesh said:
7 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.
Thangapandiyan said:
1 decade ago
We have add platform lengthe(x) + tranin length(300) = total lenght (because the train enginee is pass the platform in 36 sec not tail of the train) Now we using m/s = speed formula to find unknown platform length
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
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
Lekh Raj ghallet said:
9 years ago
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.
Carlo said:
1 decade ago
Explanation is right.
Distance = time * speed.
Distance or length = 20 * 15 = 300m.
We can't take 36 * 15 because we already used 36 sec to get 540m
so to get the relative speed:
x + 300 = 540.
x = 240m.
Distance = time * speed.
Distance or length = 20 * 15 = 300m.
We can't take 36 * 15 because we already used 36 sec to get 540m
so to get the relative speed:
x + 300 = 540.
x = 240m.
Ajit said:
1 decade ago
First find out gap of time between train and man, then multiple train speed, then we got platform length.
Gap time = 36-20 = 16.
Then, train speed = 54*5/18 = 15 m/s.
Now, platform length = 16*15 = 240 m.
Gap time = 36-20 = 16.
Then, train speed = 54*5/18 = 15 m/s.
Now, platform length = 16*15 = 240 m.
Arzoo said:
9 years ago
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.
So please give me solution regarding this.
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