Aptitude - Problems on Trains - Discussion
Discussion Forum : Problems on Trains - General Questions (Q.No. 18)
18.
A 300 metre long train crosses a platform in 39 seconds while it crosses a signal pole in 18 seconds. What is the length of the platform?
Answer: Option
Explanation:
| Speed = |  |
300 |  |
m/sec = | 50 | m/sec. |
| 18 | 3 |
Let the length of the platform be x metres.
| Then, | |
x + 300 | |
= | 50 |
| 39 | 3 |
3(x + 300) = 1950
x = 350 m.
Discussion:
39 comments Page 4 of 4.
Atique said:
1 decade ago
Why should I take 300/18 ? Why shouldn't I take 300/39 ?
Please give explanation.
Please give explanation.
Ramesh said:
1 decade ago
How that 50/3 is coming?
Pooja said:
1 decade ago
Hey can you please help me I am not getting 3(x+300)/39=50/3?
Pooja said:
1 decade ago
How 50/3 is coming?
Vijaya said:
1 decade ago
Speed 50/3 is correct. Because platform has a length. But pole doesnt. Its only a point that the train crossed. So the distance covered when it crosses the pole is just the train's length.
That is 300 metres. So the train moves at a speed of 300 metres per 18 seconds. Speed is 300/18. Hence 50/3.
That is 300 metres. So the train moves at a speed of 300 metres per 18 seconds. Speed is 300/18. Hence 50/3.
Bhaskar said:
10 years ago
Why don't we add 39 seconds + 18 seconds as the train is travelling in the same direction?
Vinayaka N said:
10 years ago
Can anyone explain?
Why don't we add 39 seconds + 18 seconds as the train is travelling in the same direction as like in other previous problems?
Why don't we add 39 seconds + 18 seconds as the train is travelling in the same direction as like in other previous problems?
Rishi said:
9 years ago
First, calculate a speed of the train.
Length = Speed * Time.
Then, S = L/T.
300/18 = 16.66 m/s.
Then, L = S * T.
(x + 300) = 16.66 * 39.
X = 350 m.
Length = Speed * Time.
Then, S = L/T.
300/18 = 16.66 m/s.
Then, L = S * T.
(x + 300) = 16.66 * 39.
X = 350 m.
Rahul said:
9 years ago
Difficult to understand this calculation.
Is there any shortcut method?
Is there any shortcut method?
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