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:
202 comments Page 5 of 21.
Ando Lawrence said:
7 years ago
Accurate Answer is 89 sec only.
@All.
In case of crossing a man/post/pole:
Usually, we will ignore the length of man/post/pole. If you want the result of speed in 'millimetres/second' accuracy, you can add length of the man or pole to the length of the train.
@All.
In case of crossing a man/post/pole:
Usually, we will ignore the length of man/post/pole. If you want the result of speed in 'millimetres/second' accuracy, you can add length of the man or pole to the length of the train.
Jellli said:
1 decade ago
Hi, I think
1.first we have to find speed of the train
s=240/24=10(in cond of the the train sross the pole)
2.then the same cross the platform of 630m then t=?
s=d/t
t=d/s=(240+650)/10(here we have to add the both len of train and platform)
=89s
1.first we have to find speed of the train
s=240/24=10(in cond of the the train sross the pole)
2.then the same cross the platform of 630m then t=?
s=d/t
t=d/s=(240+650)/10(here we have to add the both len of train and platform)
=89s
Saiyam said:
1 decade ago
Length of platform = 640m
and entire train length = 240m
the Q. is we have to find time taken by train to pass entire platform.
so we include train length utill its last coach passing the platform.
time considered up to its last coach left the platform.
ok.
and entire train length = 240m
the Q. is we have to find time taken by train to pass entire platform.
so we include train length utill its last coach passing the platform.
time considered up to its last coach left the platform.
ok.
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
Tulsi said:
1 decade ago
The distance taken by the train is nothing but the time taken by the train to cross the pole so ... the train passing the pole(time) is 24sec.
ie 240m ->24
slly
650->65sec.
The total time taken by the train to passing the station is=65+24=89sec.
ie 240m ->24
slly
650->65sec.
The total time taken by the train to passing the station is=65+24=89sec.
Tulsi said:
1 decade ago
The distance taken by the train is nothing but the time taken by the train to cross the pole so ... the train passing the pole(time) is 24sec.
ie 240m ->24
slly
650->65sec.
The total time taken by the train to passing the station is=65+24=89sec.
ie 240m ->24
slly
650->65sec.
The total time taken by the train to passing the station is=65+24=89sec.
Momena said:
9 years ago
In case of passing a pole,
length of the train = speed * time.
So speed = 240 ÷ 24,
=10 m/s.
In case of passing a platform,
Length of train + length of platform = speed * time.
then,
240 + 650 = 10 * time,
So, time = (240 + 650)/10,
= 89m/s.
length of the train = speed * time.
So speed = 240 ÷ 24,
=10 m/s.
In case of passing a platform,
Length of train + length of platform = speed * time.
then,
240 + 650 = 10 * time,
So, time = (240 + 650)/10,
= 89m/s.
Sai said:
8 years ago
Since the train has to cross the platform, it is not on the platform. It has to completely cross the platform means it crosses it's length.
Therefore total distance becomes train's length+ platform's length =890m.
Time = 890/10 = 89sec.
Therefore total distance becomes train's length+ platform's length =890m.
Time = 890/10 = 89sec.
Subhash said:
9 years ago
I think the answer is 65 sec.
Suppose:
=> 240m
Require time 24sec.
So time = 240/24 = 10m/s.
It means train speed is 10 m/s.
=> 650m.
So time = 650/10 = 65 sec.
It will ask only for 650m length.
Not consider total distance.
Suppose:
=> 240m
Require time 24sec.
So time = 240/24 = 10m/s.
It means train speed is 10 m/s.
=> 650m.
So time = 650/10 = 65 sec.
It will ask only for 650m length.
Not consider total distance.
Sumi said:
1 decade ago
Why do you want the pole length here you just wana find the length of the platform we use the pole length as the reference point only to calculate the length of the train for platform instead of pole length add the platform length.
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