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 18 of 28.
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
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.
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).
Rock said:
10 years ago
Train speed = 15 m/s.
Time different = 36-20 = 16 sec.
Length of platform is 16*15 = 240 meter.
Time different = 36-20 = 16 sec.
Length of platform is 16*15 = 240 meter.
Kumarchandana said:
10 years ago
It is one of the similar way of improving our aptitude knowledge.
Kiran said:
10 years ago
Speed of the train will be null.
Suraj said:
10 years ago
First convert km/h into m/sec:
= 54*5/18 = 15.
= 15*36-15*20 = 240.
= 54*5/18 = 15.
= 15*36-15*20 = 240.
Vicky said:
10 years ago
@Suraj we can also apply direct formula of speed on 15.
= 54*5/18 = 15.
Speed = Distance/Time.
15 = X/36-20.
X = 240.
Here 36-20 because both are in towards direction.
= 54*5/18 = 15.
Speed = Distance/Time.
15 = X/36-20.
X = 240.
Here 36-20 because both are in towards direction.
Srinivas said:
10 years ago
Actually, here it is asked for platform and train passed the platform. It doesn't matter train passed the man's distance. It's simple L = S*T but why you are including passed by man's time?
Appalaraju said:
9 years ago
d = s*t;
So d = 15 m.
l = x;
x/36-20 = 15.
x = 240.
So d = 15 m.
l = x;
x/36-20 = 15.
x = 240.
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