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 15 of 28.
Swamy said:
10 years ago
Well,
36 sec - 20 sec = 16 sec.
Then,
36 sec ----- 540 mt.
16 sec ----240 mt (train length).
36 sec - 20 sec = 16 sec.
Then,
36 sec ----- 540 mt.
16 sec ----240 mt (train length).
Sangam said:
1 decade ago
Hi guy's.
Length of the train w.r.t reference point = (54*5/18)*20 = 300 m.
Consider platform platform x meter.
Distance = Speed*Time.
(X+300) = (15*36) = 540.
X = 540-300 = 240 m.
Therefore length of platform is 240 m.
Length of the train w.r.t reference point = (54*5/18)*20 = 300 m.
Consider platform platform x meter.
Distance = Speed*Time.
(X+300) = (15*36) = 540.
X = 540-300 = 240 m.
Therefore length of platform is 240 m.
Praveen said:
1 decade ago
s = d/ t.
Length of train = s*t = 15 m/sec*20 sec = 300 m.
Now let length of platform = x m.
Total length = (300+x) m.
s = d/t.
15 = 300+x/36.
As 123 answer = 250 m
Length of train = s*t = 15 m/sec*20 sec = 300 m.
Now let length of platform = x m.
Total length = (300+x) m.
s = d/t.
15 = 300+x/36.
As 123 answer = 250 m
Shubham Gupta said:
1 decade ago
s = d/ t.
Length of train = s*t = 15 m/sec*20 sec = 300 m.
Now let length of platform = x m.
Total length = (300+x) m.
s = d/t.
15 = 300+x/36.
x = 240 m answer.
Length of train = s*t = 15 m/sec*20 sec = 300 m.
Now let length of platform = x m.
Total length = (300+x) m.
s = d/t.
15 = 300+x/36.
x = 240 m answer.
Rasik said:
1 decade ago
Guys the total time to cross the platform is 36 sec with speed of 15 m/sec i.e. d=s*t.
36*15=540 m. Hence option is none of these.
36*15=540 m. Hence option is none of these.
Paridhi said:
1 decade ago
Should we not consider the length of man? Why do we take it as a reference point?
Swagath said:
1 decade ago
Thanks for sharing the useful information.
SantiagoArg said:
1 decade ago
Who says the man is standing in the platform?
Premchandra saka said:
1 decade ago
First calculate length of both platform and train = (Train cross the platform)*Train speed in second = 36*(54*5/18) = 540 meter.
Then Train length = Speed in meter per second*Cross the man in second.
= 15 m/sec*20 sec = 300 meter.
Now, Platform length = Both platform and train length - Train length.
= 540 meter-300 meter.
= 240 meter.
Then Train length = Speed in meter per second*Cross the man in second.
= 15 m/sec*20 sec = 300 meter.
Now, Platform length = Both platform and train length - Train length.
= 540 meter-300 meter.
= 240 meter.
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.
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