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:
285 comments Page 15 of 29.
PANASA HARISH KUMAR said:
1 decade ago
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.
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.
R.sai said:
1 decade ago
Another method we do that problem.
Train reach time-man standing time = 36-20 = 16.
Length = 15*16 = 240m.
Train reach time-man standing time = 36-20 = 16.
Length = 15*16 = 240m.
Appalaraju said:
1 decade 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.
Srinivas said:
1 decade 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?
Vicky said:
1 decade 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.
Suraj said:
1 decade 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.
Kiran said:
1 decade ago
Speed of the train will be null.
Kumarchandana said:
1 decade ago
It is one of the similar way of improving our aptitude knowledge.
Rock said:
1 decade 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.
Swamy said:
1 decade 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).
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