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 4 of 21.
Riya said:
1 decade ago
Yes it takes 65 secs for the front part of the train to reach the platform end but what we need to find is the time taken by the complete train to pass the platform.
i.e. we need to add the time taken to travel a distance equal to its own length.
i.e 65+(240/10) = 89 seconds. 65 seconds is definitely not the answer.
i.e. we need to add the time taken to travel a distance equal to its own length.
i.e 65+(240/10) = 89 seconds. 65 seconds is definitely not the answer.
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
Mir Rokon uddin. said:
8 years ago
To me, answer is 41 if the pole and the platform consider separately.
650-240=410.
Now it crosses 240m in 24s.
So, 410m in 41s.
If both pole and platform consider jointly the answer will be 89s. I understood 2nd case. But my Mind also with the 1st case. I think the question is ambiguous. Or am I wrong?
650-240=410.
Now it crosses 240m in 24s.
So, 410m in 41s.
If both pole and platform consider jointly the answer will be 89s. I understood 2nd case. But my Mind also with the 1st case. I think the question is ambiguous. Or am I wrong?
Krishna said:
1 decade ago
Data is not sufficient where is the pole length ?????
if the train is passing a platform of length 650m
then time taken = (650+240)/speed of train
speed of train = (length of train + length of pole) / 24 sec
= (240 + length of pole)/24 sec
note : 240/24 is not always correct ...
if the train is passing a platform of length 650m
then time taken = (650+240)/speed of train
speed of train = (length of train + length of pole) / 24 sec
= (240 + length of pole)/24 sec
note : 240/24 is not always correct ...
Radhakrishnan said:
8 years ago
Why can't the answer be 65 according to my explanation?
Speed of the train=(distance /time).
Hence,
240 ÷ 24 =10.
Speed of train is 10 m/s.
Time =distance /speed of the train.
For a 650m platform hence distance is 650.
Time=650m/10m/s.
Hence,
Time =65 sec.
Speed of the train=(distance /time).
Hence,
240 ÷ 24 =10.
Speed of train is 10 m/s.
Time =distance /speed of the train.
For a 650m platform hence distance is 650.
Time=650m/10m/s.
Hence,
Time =65 sec.
Rajesh said:
1 decade ago
240 m in 24 seconds.
So one second 10 m.
So platform length 650 m. It means the train just reach the end of the platform in 650 seconds. It means train not pass the platform. 240 m train is in platform. Its also going to pass.
So 650+240 = 890 m so. 89 sec. is the answer.
So one second 10 m.
So platform length 650 m. It means the train just reach the end of the platform in 650 seconds. It means train not pass the platform. 240 m train is in platform. Its also going to pass.
So 650+240 = 890 m so. 89 sec. is the answer.
Pon said:
1 decade ago
Let length of the train = l = 240m.
Time taken to cross platform = t = ?
Platform length = a = 650m.
Speed of the train = S = (length of the train+length of platform)/time taken to cross platform.
s = (240+650) /t.
s = 240/24=10m/s.
10 = 890/t.
T = 890/10 = 89sec.
Time taken to cross platform = t = ?
Platform length = a = 650m.
Speed of the train = S = (length of the train+length of platform)/time taken to cross platform.
s = (240+650) /t.
s = 240/24=10m/s.
10 = 890/t.
T = 890/10 = 89sec.
Vicky said:
1 decade ago
I'm thinking that if it takes 24 seconds to cross 240 m.
Then it takes 48 sec s to cross 480 m with constant speed.
So it takes 240 m = 24 sec.
10 m = 1 sec.
To pass 650 m it takes 65 secs. I'm sure whether this is correct or not. I'm sure that question is not clear.
Then it takes 48 sec s to cross 480 m with constant speed.
So it takes 240 m = 24 sec.
10 m = 1 sec.
To pass 650 m it takes 65 secs. I'm sure whether this is correct or not. I'm sure that question is not clear.
Patel said:
7 years ago
I think 65 is correct.
A train 240 m long passes a pole in 24 seconds.
240 is the find measurement where you find the 1 m ratio.
How long will it take to pass a platform 650 m long?
Based on finding the 1 m ratio. you have to find for 650 and that is why 65 is correct.
A train 240 m long passes a pole in 24 seconds.
240 is the find measurement where you find the 1 m ratio.
How long will it take to pass a platform 650 m long?
Based on finding the 1 m ratio. you have to find for 650 and that is why 65 is correct.
Natraj said:
9 years ago
d = 240, s = 24 sec. Total d = 650, Speed = ?.
d = total d + d = 650 + 240 = 890.
Speed = d/t = 240/24 = 10 m/s to pass a platform.
d = 650, Speed = 10 m/s, t =?
t = d/s = 890/10 = 65 sec
Even I have 65 sec as an answer. Then how to get 89 sec? Please help me.
d = total d + d = 650 + 240 = 890.
Speed = d/t = 240/24 = 10 m/s to pass a platform.
d = 650, Speed = 10 m/s, t =?
t = d/s = 890/10 = 65 sec
Even I have 65 sec as an answer. Then how to get 89 sec? Please help me.
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