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 7 of 29.
Remy said:
2 decades ago
How come (300+x) /15?its not said the man stands at the beginning of platform. If hes somwhere in the middle how come we add the length of the train 300 m ?
Gaurang said:
2 decades ago
Amit thanks for answer correctly.
Magesh said:
2 decades ago
Guys listen.
Take a point as man standing on the platform. So the moving train pass the point at the time of 20 sec.
So, Length of the train = (15 x 20)m = 300 m.
Take a point as man standing on the platform. So the moving train pass the point at the time of 20 sec.
So, Length of the train = (15 x 20)m = 300 m.
Karthik said:
2 decades ago
Shortcut:
Minus the both time of the train to cross the platform as well as man (reference point).
T = 36 sec, t = 20 sec.
T - t = 16 sec.
With the normal formula Length = Speed * Time
(i.e) 15 m/s * 16 sec = 240 metres.
Minus the both time of the train to cross the platform as well as man (reference point).
T = 36 sec, t = 20 sec.
T - t = 16 sec.
With the normal formula Length = Speed * Time
(i.e) 15 m/s * 16 sec = 240 metres.
Shelly said:
2 decades ago
Thanks Rahul.
Vivek said:
2 decades ago
speed:- 54*5/18= 15 m/sec
length of the train:-15*20= 300 m.(distance= speed * time)
length of the platform:-x
Speed = Distance /Time
15=300+x/36
300+x=540
x=540-300
x=240
length of the train:-15*20= 300 m.(distance= speed * time)
length of the platform:-x
Speed = Distance /Time
15=300+x/36
300+x=540
x=540-300
x=240
Kranthi said:
2 decades ago
As they asked only platform length why isn't it 35X15=540...
why should we substract...??
why should we substract...??
Satheesh said:
2 decades ago
Hi Guys
1 Km=1000 Meters
1 hr=3600 seconds
If the speed of the train is 54 km/hr
54*1000= 54000
54000/3600=15
A train passes a station platform in 36 seconds
15*36=540
a man standing on the platform in 20 seconds
15*20=300
540-300=240
Ans:240 Simple
1 Km=1000 Meters
1 hr=3600 seconds
If the speed of the train is 54 km/hr
54*1000= 54000
54000/3600=15
A train passes a station platform in 36 seconds
15*36=540
a man standing on the platform in 20 seconds
15*20=300
540-300=240
Ans:240 Simple
Divya said:
2 decades ago
I solved in dis manner
54*(5/18)=15
speed =15m/sec
it crossed d platform within 36 secs
for 20 sec=?
36-20=16
16*15=240m
54*(5/18)=15
speed =15m/sec
it crossed d platform within 36 secs
for 20 sec=?
36-20=16
16*15=240m
Arun said:
2 decades ago
@divya :yeah... Its good..
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