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 20 of 28.
Er.Shubham said:
7 years ago
@Krishna,
Don't compare the Length of both.
Take only the starting and ending point.
Don't compare the Length of both.
Take only the starting and ending point.
Ramya said:
6 years ago
Please explain, how come 15*20?
Length of the train means we have to do 15*36, right?
Length of the train means we have to do 15*36, right?
Noradavis said:
3 years ago
@All.
Since the train is moving toward the man you can do 36-20 seconds = 16 seconds.
Since the train is moving toward the man you can do 36-20 seconds = 16 seconds.
(8)
Aasif Javed said:
1 decade ago
@Ashwini is your calculation right?
Please check it.
x = 54*5/18*36 = 540m not 240m
Please check it.
x = 54*5/18*36 = 540m not 240m
Ani said:
7 years ago
Net time = 36-20 = 16,
So length of platform is =time * speed,
That is=16x15=240 MTR.
So length of platform is =time * speed,
That is=16x15=240 MTR.
Manonmani said:
1 decade ago
I also having doubt.
Why we took 20 sec (300=20*15).
Instead of 30sec (450=30*15).
Why we took 20 sec (300=20*15).
Instead of 30sec (450=30*15).
Paridhi said:
1 decade ago
Should we not consider the length of man? Why do we take it as a reference point?
Jinita said:
1 decade ago
Why took 15*20? and the method (36-20) i.e. taking difference can be applicable?
Krunal mistry said:
1 year ago
Why do we choose 20sec in finding distance and not 36sec?
Please explain to me.
Please explain to me.
(34)
Sridhar said:
3 years ago
Speed = 15mtr/hr.
15*20 = 15 * 36,
300 = 540.
= 540 - 300.
Length = 240.
15*20 = 15 * 36,
300 = 540.
= 540 - 300.
Length = 240.
(11)
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