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:
282 comments Page 5 of 29.
Rakesh said:
5 years ago
I have solved this problem in a different way, is this the right way to solve it?
Speed=15 m/sec.
Total length of train is 300m,
let length of the plateform be x m,
total distance = speed * time,
x + 300 = 15*36,
x + 300 = 540,
x = 240m.
Speed=15 m/sec.
Total length of train is 300m,
let length of the plateform be x m,
total distance = speed * time,
x + 300 = 15*36,
x + 300 = 540,
x = 240m.
(4)
Sharath Naik said:
5 years ago
Why they have taken 20 sec. Can we take 30 sec also? Please explain.
Keerthi said:
5 years ago
Why we, not multiple 15 * 36 instead we multiple 15 * 20? Please explain.
Jai said:
5 years ago
t1-t2 = 36 - 26 = 16.
We know 54 x 5/18=15,
So putting in formula s=d/t.
15 = d/16, where d is taken as length here;
d = 15 * 16,
= 240.
We know 54 x 5/18=15,
So putting in formula s=d/t.
15 = d/16, where d is taken as length here;
d = 15 * 16,
= 240.
Aniket Masalkhamb said:
5 years ago
You can multiply 15 * 36 which gives you 540m then x be the length of the platform therefore as speed = distance upon time 540 +x/20 = 15.
x = 240m.
x = 240m.
Udaya said:
5 years ago
Shortcut method:-
Train + Platform = 36 sec.
Train = 20sec.
Extra it takes 16 sec to travel platform.
Covert kmph to m/s because we need answer in m/ s.
54kmph*5/18 = 15m/s.
15* 20 = 300m train length.
It takes 20 sec ---> 300m
16sec ---> ?????
Less by more concept 16/20 *300 = 240 m.
Train + Platform = 36 sec.
Train = 20sec.
Extra it takes 16 sec to travel platform.
Covert kmph to m/s because we need answer in m/ s.
54kmph*5/18 = 15m/s.
15* 20 = 300m train length.
It takes 20 sec ---> 300m
16sec ---> ?????
Less by more concept 16/20 *300 = 240 m.
(2)
Manikandan said:
5 years ago
From the given data, we can consider the only man as a reference point to find the length of train. So let us consider man is standing at the beginning, so 15*20 will be enough to find the length of the train, Am I right?
Jackiep said:
6 years ago
Time taken to pass a station = 36s.
Time taken to pass a man = 20s.
Difference=16s.
We have,
Distance = Speed X Time.
= 15 X 16.
= 240m.
Time taken to pass a man = 20s.
Difference=16s.
We have,
Distance = Speed X Time.
= 15 X 16.
= 240m.
(1)
Avinash Kapu said:
6 years ago
In this problem, it is considered that the man is standing at the extreme end. That's the reason length of the train is calculated as 15*20. What if the man is standing in the middle of the platform.
Tayek said:
6 years ago
Thanks @Satheesh.
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