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 10 of 28.
Gaurav said:
7 years ago
A simple one trick:
Here train crosses a platform and a man standing on a platform in the same direction i.e. 36 - 20 = 16 sec is relative timing.
And speed of the train is 54 km/hr i.e. 15 m/sec
Now we have speed and time then apply formula;
The solution is length= 15 x 16 = 240 m.
That's all.
Thank you.
Here train crosses a platform and a man standing on a platform in the same direction i.e. 36 - 20 = 16 sec is relative timing.
And speed of the train is 54 km/hr i.e. 15 m/sec
Now we have speed and time then apply formula;
The solution is length= 15 x 16 = 240 m.
That's all.
Thank you.
Bikash said:
8 years ago
If the man stand at the head side then the length of train is 300m as well as the length of the platform is 240 m and if the man stand at any point of the platform then the length of the platform is 540.
Pria said:
8 years ago
What is reference point?
Satish said:
8 years ago
Let distance be x m.
Time take for crossing platform=36sec.
For a man on the same platform=20 sec.
Speed=D/T, we get speed of train=54*5/18=15m/sec.
Since the man is on the same platform we can subtract the time from entire time=36-20=16
So, S=D/T
15=x/16.
Then, x=15*16=240m.
That's all.
Time take for crossing platform=36sec.
For a man on the same platform=20 sec.
Speed=D/T, we get speed of train=54*5/18=15m/sec.
Since the man is on the same platform we can subtract the time from entire time=36-20=16
So, S=D/T
15=x/16.
Then, x=15*16=240m.
That's all.
Varad shinde said:
8 years ago
He guys,
In the problem, there is a common formula used from the examiner is,
Distance = Speed x Time.
In the problem, there is a common formula used from the examiner is,
Distance = Speed x Time.
Dharmendra (dj) said:
8 years ago
As we know,
A train passes a station platform in 36 seconds and man standing on the platform in 20 second.
We have speed of train is 15m/s,
So,
We know a man standing and train crossing platform
36-20=16 sec
Now we have actual time
Then distance= Time x speed
X. = 16x15 m/s
X= 240 m
Distance=240m.
A train passes a station platform in 36 seconds and man standing on the platform in 20 second.
We have speed of train is 15m/s,
So,
We know a man standing and train crossing platform
36-20=16 sec
Now we have actual time
Then distance= Time x speed
X. = 16x15 m/s
X= 240 m
Distance=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.
Zainab said:
8 years ago
@Frank.
Good explanation.
Good explanation.
Rabiul said:
8 years ago
What is the relation between 'standing a man 20 sec''' and 'train length''?
A.m.manojkumar said:
8 years ago
Consider the man standing starting edge of platform. The train passes him in 20 sec means, we can measure the length of the train.
So, length of the train is,
(54km/3600sec)*20sec=300m.
Now train passed him,
Train =============>
Platform ########
Man $
From the above graph, 300m length train crossed him in 20 sec. Remaining 16sec train takes to cross the platform.
So,
Length of the platform is,
(300m/20sec)*16sec=240m.
So, length of the train is,
(54km/3600sec)*20sec=300m.
Now train passed him,
Train =============>
Platform ########
Man $
From the above graph, 300m length train crossed him in 20 sec. Remaining 16sec train takes to cross the platform.
So,
Length of the platform is,
(300m/20sec)*16sec=240m.
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