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?
320 m
350 m
650 m
Data inadequate
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 2 of 4.

Akhila said:   7 years ago
A simple and Understandable explanation, Thanks. @Sundar.

VENU said:   7 years ago
Speed = distance/time.
so i.e 300/18 =50/3.
Let distance of pltfrm is X.
so time taken by the trn to cross platform =(X+300)/50/3 =39,
i.e X+300=(39*50)/3,
650-300=X,
X=350.
(2)

Hemanth said:   7 years ago
In this problem, speed is not given then how to take 300/18?
(1)

Abhi said:   7 years ago
@Sundar.

Thanks For the explanation.

Archana said:   8 years ago
How it's 350? I didn't understand please tell me the answer.

Amrendra mishra said:   8 years ago
Let, Length of platform being static will be-(300+x).
and, the speed of train while passing pole is -300/18=150/9.
Hence;-
150/9=(300+x)/39,
x=350 ans.

Chakri said:   8 years ago
The speed to cross the pole and the platform is same there is no change in speed but why we have to take 18 sec?

Nikita said:   8 years ago
Thank you @Umesh.

Masud said:   8 years ago
@Koushik Roy.

300/18 m/s, it's the speed of train.

Akshitkumar said:   9 years ago
Tell the shortcut in detail.


Post your comments here:

Your comments will be displayed after verification.