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:
282 comments Page 6 of 29.
Satish said:
8 years ago
Let distance be x m.
Time take for crossing platform=36sec.
For a man on the same platform=20 sec.
Speed=D/T, we get speed of train=54*5/18=15m/sec.
Since the man is on the same platform we can subtract the time from entire time=36-20=16
So, S=D/T
15=x/16.
Then, x=15*16=240m.
That's all.
Time take for crossing platform=36sec.
For a man on the same platform=20 sec.
Speed=D/T, we get speed of train=54*5/18=15m/sec.
Since the man is on the same platform we can subtract the time from entire time=36-20=16
So, S=D/T
15=x/16.
Then, x=15*16=240m.
That's all.
RKK said:
1 decade ago
Speed = 54*(5/18) m/sec. = 15 m/sec.
length between man and starting point of platform = (15*20) = 300 m.
x be the length between man and end point of platform and train cross the total length in 36 sec.
So,
300 + x is the total length of platform.
(300 + x)/36 = 540.
Ans = 240 m.
length between man and starting point of platform = (15*20) = 300 m.
x be the length between man and end point of platform and train cross the total length in 36 sec.
So,
300 + x is the total length of platform.
(300 + x)/36 = 540.
Ans = 240 m.
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:
2 decades 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:
8 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.
Hemant said:
2 weeks ago
@All.
First, identify the distance:
> Crossing a man/pole/tree?
Distance = Length of the train.
> Crossing a platform/bridge/tunnel?
Distance = Length of train + Length of platform.
> Crossing another train?
Distance = Length of Train A + Length of Train B.
First, identify the distance:
> Crossing a man/pole/tree?
Distance = Length of the train.
> Crossing a platform/bridge/tunnel?
Distance = Length of train + Length of platform.
> Crossing another train?
Distance = Length of Train A + Length of Train B.
(1)
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:
9 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?
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers