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 6 of 28.
Sachin kamble said:
1 decade ago
Train passes the plat form in 36 sec and man standing on platform i.e 20 sec so the time 16 sec by 36-20=16 then apply speed=distance/time we have speed 54km/hr that to be converted in to m/sec because we need length in meter. So 54*[5/18] = 15 m/sec.
Then distance = 16*15 = 240.
Then distance = 16*15 = 240.
Amol said:
1 decade ago
Friends I think time req. To cross man (20) is less than time req. To cross station (36). So length of station is more than length of train.
So,
Total length of station = 20sec*15m/sec + 16sec*15m/sec.
= lth of train + remaining lth of platform.
For 16 sec,
= 300+240.
= 540m.
So,
Total length of station = 20sec*15m/sec + 16sec*15m/sec.
= lth of train + remaining lth of platform.
For 16 sec,
= 300+240.
= 540m.
Saikrushna said:
1 decade ago
If the train cross the platform in 36 sec. Ok in the same time it also cross it's own length of 300 mt. Then we have to subtract the time taken by the train passing it's own length i.e. 20sec.
Then the platform length should be crossed in (36-20) sec =16 sec. Then why (36+20) sec?
Then the platform length should be crossed in (36-20) sec =16 sec. Then why (36+20) sec?
Nasir Shaikh said:
1 decade ago
Consider man is standing at the start of Platform,it takes 20 secs to cross man, but length of platorm is more than man.
Length of train = 15 * 20 = 300 m
But at 15 m/s train will last tip will take 16 more secs to cross platform i.e length of platform is 16 * 15 = 240 m
Length of train = 15 * 20 = 300 m
But at 15 m/s train will last tip will take 16 more secs to cross platform i.e length of platform is 16 * 15 = 240 m
Irfan Zahir said:
7 years ago
Speed conversion, 54*(5/18)= 15 m/s.
Length of both Train and Platform is;
D=S*T,
= 15*36,
= 540 (It includes the length of both train and platform).
Again,
D=S*T
=15*20,
= 300 (It is the length of only train),
Now the length of the platform = 540-300= 240 meter.
Length of both Train and Platform is;
D=S*T,
= 15*36,
= 540 (It includes the length of both train and platform).
Again,
D=S*T
=15*20,
= 300 (It is the length of only train),
Now the length of the platform = 540-300= 240 meter.
Sangram said:
1 decade ago
In simple process,
Bs-------------------m------------Be
A--------20S---------B------16S---C
l---------------36s---------------l
If man was reference point then T.P=36-20=16s.
We know length=speed*time.
Then lenth of train=(54*5/18)*16=15m/s.*16s.=240m.
Answer=240m.
Bs-------------------m------------Be
A--------20S---------B------16S---C
l---------------36s---------------l
If man was reference point then T.P=36-20=16s.
We know length=speed*time.
Then lenth of train=(54*5/18)*16=15m/s.*16s.=240m.
Answer=240m.
Harish said:
8 years ago
For finding length of the train we must consider a reference point (man).
But for finding the distance covered why do we need the length of the train.
Simply we can do DISTANCE COVERED = SPEED X TIME.
Can anyone explain it, whether this is correct method are wrong?
But for finding the distance covered why do we need the length of the train.
Simply we can do DISTANCE COVERED = SPEED X TIME.
Can anyone explain it, whether this is correct method are wrong?
Keerthi said:
1 decade ago
If the person is standing at the starting point of the platform means the platform length is 240m otherwise its length cannot be calculated. Because if the person standing between any point of platform means it will addition of part of platform and length of train.
Shoeb said:
1 decade ago
Distance=Time*Speed.
* 54 x 5/18 = 15
* 15 x 20(given) = 300
* x+300/36=15
=240m
OR
* Distance = speed*time
* Distance = (54*5/18)*(36-20)
= 15*16
= 240
Speed , Time is given to us. We have to only apply the formula in proper way.
* 54 x 5/18 = 15
* 15 x 20(given) = 300
* x+300/36=15
=240m
OR
* Distance = speed*time
* Distance = (54*5/18)*(36-20)
= 15*16
= 240
Speed , Time is given to us. We have to only apply the formula in proper way.
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)
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers