Aptitude - Problems on Trains - Discussion
Discussion Forum : Problems on Trains - General Questions (Q.No. 6)
6.
A train 240 m long passes a pole in 24 seconds. How long will it take to pass a platform 650 m long?
Answer: Option
Explanation:
| Speed = |  |
240 |  m/sec = 10 m/sec. |
| 24 |
 Required time = |
|
240 + 650 | sec = 89 sec. |
| 10 |
Discussion:
206 comments Page 15 of 21.
Vipul said:
1 decade ago
Whoever thinks it is 65m, take a look.
length of platform is 650 m long, and length of train is 240m.
Train can't cross the platform by just travelling 650m, it has to travel 240m more so that its last bogie crosses the platform.
Therefore train has to travel total distance 650+240=890m to cross the platform.
And its speed is 10m/s, therefor it will take 89 sec.
length of platform is 650 m long, and length of train is 240m.
Train can't cross the platform by just travelling 650m, it has to travel 240m more so that its last bogie crosses the platform.
Therefore train has to travel total distance 650+240=890m to cross the platform.
And its speed is 10m/s, therefor it will take 89 sec.
Jawahar said:
1 decade ago
Answer should be 65. Because in question it doesn't mentioned as total time to cross. Question itself says that. I don't know why to add both. If they mentioned as "total time to cross" then the answer 89 is true.
Chandu said:
1 decade ago
650/240=x/24 and x=65sec then total time is 65sec +24sec=89sec.
Eswar said:
1 decade ago
240m=24sec.
890m=?
Train length+platform length=240+650=890m.
=24*890/240.
=89.
890m=?
Train length+platform length=240+650=890m.
=24*890/240.
=89.
Akhila said:
1 decade ago
@Pooja.
Here we must add 240. Because the total length is expressed as length of the train + length of the platform.
(i.e) 240+650=890.
Here we must add 240. Because the total length is expressed as length of the train + length of the platform.
(i.e) 240+650=890.
Pooja said:
1 decade ago
Can any tell me why there is need to add 240 ?
Vijay said:
1 decade ago
How can u know that the pole is on the platform.
if the pole is not on the platform,the ans is 65
240/24=650/t2
t2=65
if the pole is not on the platform,the ans is 65
240/24=650/t2
t2=65
Vijay said:
1 decade ago
As per the given data,the question didn't tell about the pole is on the platform or not.
so,speed = distance/time
speed = 240m/24sec
= 10 m/sec
here speed is same to cross platform as well as pole
so,
D1/T1 = D2/T2
240m/24sec = 640m/T2
10 = 640/T2
T2 = 64 sec
so,speed = distance/time
speed = 240m/24sec
= 10 m/sec
here speed is same to cross platform as well as pole
so,
D1/T1 = D2/T2
240m/24sec = 640m/T2
10 = 640/T2
T2 = 64 sec
Swetha said:
1 decade ago
Here no need of calculating the speed, as speed is same we can directly calculate as below:
(d1/t1) = (d2/t2).
(240/24) = ((240+650) /x).
X=89sec.
(d1/t1) = (d2/t2).
(240/24) = ((240+650) /x).
X=89sec.
Rasim said:
1 decade ago
We can calculate the train speed by considering pole as a reference point
train length=240m
time taken by a train to pass a pole =24sec
s=d/t
s=(240/24)
s=10m/sec
platform length=650m
we know that
total distance=speed*time
650+240=10*t
890=10*t
t=89sec
train length=240m
time taken by a train to pass a pole =24sec
s=d/t
s=(240/24)
s=10m/sec
platform length=650m
we know that
total distance=speed*time
650+240=10*t
890=10*t
t=89sec
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