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.
Nusrath Kamal said:
1 decade ago
Why you all are complicating this simple question, here how this work:
Answer = Length of the Train - Length of the platform
Length of the Train= Speed + Time (please refer the formula).
: 54 * 5/18 = 15(speed of the train)X 20 Time = 300
Length of the Platmform= Speed + Time
: 54 * 5/18 = 15 (Speed of the Train) X 36 Time = 540
So answer = 540 - 300 = 240 M
Answer = Length of the Train - Length of the platform
Length of the Train= Speed + Time (please refer the formula).
: 54 * 5/18 = 15(speed of the train)X 20 Time = 300
Length of the Platmform= Speed + Time
: 54 * 5/18 = 15 (Speed of the Train) X 36 Time = 540
So answer = 540 - 300 = 240 M
Ashwini Shet said:
1 decade ago
Is it necessary to calculate the length of the train?
We can do it directly as:
distance = speed * time
Let x be the length of the platform , which train crosses in 36s.
x = 54 *5/18 *36 = 240m
We can do it directly as:
distance = speed * time
Let x be the length of the platform , which train crosses in 36s.
x = 54 *5/18 *36 = 240m
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
Dheeraj said:
1 decade ago
Can some tell me which formula we are applying for for
x+300
-----=15
36
I understood that once we multiply 15 and 36 we will get 540......
But, why we are multiplying them......?
Is it because of distance = speed * Time.....???
Explain me please???
x+300
-----=15
36
I understood that once we multiply 15 and 36 we will get 540......
But, why we are multiplying them......?
Is it because of distance = speed * Time.....???
Explain me please???
Baskar.R said:
1 decade ago
Speed = 54x5m/sec = 15 m/sec
15*36=540
man standing= 15*20=300
ans= platform length=540-200
ans= 240
15*36=540
man standing= 15*20=300
ans= platform length=540-200
ans= 240
Rahul said:
1 decade ago
Please tell me the reason why we can not calculate lenght of train through 15*36=540 can we calculate lenght of train like this if nt thn tell me reason.
Ranjitha said:
1 decade ago
Actually the answer can b 540.
15*36=540.
15*36=540.
Mohd Imran said:
1 decade ago
Hi friends,
length of the platform = speed*time
so,speed =54km\hr
1km=1000
1hr=60*60=3600secs
so,km/hr=1000/3600=5/18
km/hr=0.2777
so,speed =54*0.277=15
and time=36-20=16.
so length of the platform=speed*time=15*16
length of the speed =240m.
so the answer is(b)
length of the platform = speed*time
so,speed =54km\hr
1km=1000
1hr=60*60=3600secs
so,km/hr=1000/3600=5/18
km/hr=0.2777
so,speed =54*0.277=15
and time=36-20=16.
so length of the platform=speed*time=15*16
length of the speed =240m.
so the answer is(b)
Sujay Kumar Sardar said:
1 decade ago
@Ranjita
No Ranjita. 540m is the total distance(length) covered by train i.e its own
Length plus length of the platform= 540m
Though we know length of the train i.e 300m
Therefore length of the platform is (540m-300m)= 240m.
No Ranjita. 540m is the total distance(length) covered by train i.e its own
Length plus length of the platform= 540m
Though we know length of the train i.e 300m
Therefore length of the platform is (540m-300m)= 240m.
Rajasekhar sarvepalli said:
1 decade ago
Since the train is moving toward the man you can do 36-20 seconds = 16 seconds.
Logically if u think whenever u stand on a platform and train is coming towards you the the speed of a man becomes lesser than the speed of a train.
there for distance = speed x time = (54 x 1000 meters/ 3600 seconds).x 16 sec
= 15 x 16
= 240 meters
Logically if u think whenever u stand on a platform and train is coming towards you the the speed of a man becomes lesser than the speed of a train.
there for distance = speed x time = (54 x 1000 meters/ 3600 seconds).x 16 sec
= 15 x 16
= 240 meters
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