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 8 of 28.
Jyoti prakash giri said:
9 years ago
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.
It should take the tip as the entry and tail as exit and by that time it would have covered 600 m.
Vishnu said:
6 years ago
The train has to pass the platform.
It means the tail end of the train has to pass the end of the platform. So the distance of the platform + length of the train has to be considered as distance travelled by train for 36 seconds.
It means the tail end of the train has to pass the end of the platform. So the distance of the platform + length of the train has to be considered as distance travelled by train for 36 seconds.
T navakrishna said:
1 decade ago
As man length is negligible than the train length so length of the train crossing the person is 15*20.
So time taken by the train is 20 sec and time taken by the train to cross the platform is 36 sec don't get get confused here.
So time taken by the train is 20 sec and time taken by the train to cross the platform is 36 sec don't get get confused here.
Sujay Kumar Sardar said:
1 decade ago
@Ranjita
No Ranjita. 540m is the total distance(length) covered by train i.e its own
Length plus length of the platform= 540m
Though we know length of the train i.e 300m
Therefore length of the platform is (540m-300m)= 240m.
No Ranjita. 540m is the total distance(length) covered by train i.e its own
Length plus length of the platform= 540m
Though we know length of the train i.e 300m
Therefore length of the platform is (540m-300m)= 240m.
Siddhant ojha said:
8 years ago
Better approach would be.
15*36=540 which is the overall distance covered and then subtracting the length of the train form it.
Which is 15 * 20=300.
So, 540-300=240.
In this case, you will not need to solve the equation for x.
15*36=540 which is the overall distance covered and then subtracting the length of the train form it.
Which is 15 * 20=300.
So, 540-300=240.
In this case, you will not need to solve the equation for x.
M.Ramya Devi said:
1 decade ago
Speed of the train=54km/hr.
Speed=54*5/18=15.
Train passes a station platform:Length=speed*time.
=15*36=540.
Train passes the man standing on the platform:Length=speed*time.
=15*20=300.
Length of the platform=540-300=240m.
Speed=54*5/18=15.
Train passes a station platform:Length=speed*time.
=15*36=540.
Train passes the man standing on the platform:Length=speed*time.
=15*20=300.
Length of the platform=540-300=240m.
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.
Mounika said:
7 years ago
36 sec is the length of the train and platform. 20 seconds is the length of the train.
So, the length of the platform is 36-20=16 sec.
54*5/18 = 15m/sec is the speed of the train.
The length of the platform = 15*16 = 240.
So, the length of the platform is 36-20=16 sec.
54*5/18 = 15m/sec is the speed of the train.
The length of the platform = 15*16 = 240.
Omkar Nivalagi said:
6 years ago
Simply;
Find speed in m/sec
54*(5/18).
And the difference between two lengths from plat1 to plat2 i,e (36-20)=16 and this is to the time taken to cross length plat1 to plat2 in secs.
As we know s=d/t;
5/18*16=240; answer
Find speed in m/sec
54*(5/18).
And the difference between two lengths from plat1 to plat2 i,e (36-20)=16 and this is to the time taken to cross length plat1 to plat2 in secs.
As we know s=d/t;
5/18*16=240; answer
ESNALA SIDDA said:
4 weeks ago
1) First calculate the train distance.
D = S×T.
S = 54×5/18,
S = 15m/s,
D = 15×20 = 300m.
2) Calculate the platform + train distance.
D = 36×15
= 540m
Platform distance
540 - 300 = 240m.
D = S×T.
S = 54×5/18,
S = 15m/s,
D = 15×20 = 300m.
2) Calculate the platform + train distance.
D = 36×15
= 540m
Platform distance
540 - 300 = 240m.
(13)
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