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 7 of 21.
Neetu said:
2 decades ago
We are adding 240 and 650 because the train needs to cross the entire platform. CROSSING means the last coach should cross the end of the platform. That's why we are adding both lenghts.
Kiran,
We cannot solve in your way because a train will never take the same time in crossing a pole and a platform. The train crossing the pole and crossing the platform is not same.
Kiran,
We cannot solve in your way because a train will never take the same time in crossing a pole and a platform. The train crossing the pole and crossing the platform is not same.
Pavan said:
2 decades ago
Pavan,
hello dudes there is a simple common sense
The length of the train is 240m
The length of the platform is 650m
So the total dstn to cross is (240+650)
=890m
ther fore
890/spd
=890/10
=89sec
hello dudes there is a simple common sense
The length of the train is 240m
The length of the platform is 650m
So the total dstn to cross is (240+650)
=890m
ther fore
890/spd
=890/10
=89sec
Kartikey patel said:
2 decades ago
I think in question ask the time taken for only bridge 650. Then why we add both?
HARI said:
2 decades ago
Dudes,
Actually the length is calculated along with the train only as (650+240). The passing of the platform is for the train, so that, train tail has to pass the platform; Henceforth,
(Train+ Platform)is correct
Actually the length is calculated along with the train only as (650+240). The passing of the platform is for the train, so that, train tail has to pass the platform; Henceforth,
(Train+ Platform)is correct
Umesh said:
2 decades ago
A train 240 m long passes a pole in 24 seconds. How long will it take to pass a platform 650 m long?
=====> for the tail of train to clear the platform it has to pass its own length + platform length.(240+650=890 m)
for 240 m. -- 24 sec.
for 890 m
by observation 890 is @ 4 times (some less) to 240
so time is also @ 4 times of 24 (some less) i,e. 96
from options 89 is @96 & somewhat less.
=====> for the tail of train to clear the platform it has to pass its own length + platform length.(240+650=890 m)
for 240 m. -- 24 sec.
for 890 m
by observation 890 is @ 4 times (some less) to 240
so time is also @ 4 times of 24 (some less) i,e. 96
from options 89 is @96 & somewhat less.
Suki said:
2 decades ago
Neetu's explanation s very nice.
Viji said:
2 decades ago
Neetu your explanation cleared my doubt. Thanks.
Devanshu said:
2 decades ago
Its not mentioned in ques that train passes pole and platform both. There is no need to add 240 with 650.
Tasauar rabani said:
2 decades ago
Neetus explanation is excelent.
Kavi said:
1 decade ago
@Kartikey Patel & Devanshu
First Me too Think like this
if
train 240 m long passes a pole in 24 seconds.
i.e 240 m : 24 sec
then 650 m : ? sec
650*24/240=65
and the ans is 65sec
....
After Saiyam Explanation i got clearly...
bfe netu he expn.
"so we include train length utill its last coach passing the platform.
time considered up to its last coach left the platform."
Thanks...
First Me too Think like this
if
train 240 m long passes a pole in 24 seconds.
i.e 240 m : 24 sec
then 650 m : ? sec
650*24/240=65
and the ans is 65sec
....
After Saiyam Explanation i got clearly...
bfe netu he expn.
"so we include train length utill its last coach passing the platform.
time considered up to its last coach left the platform."
Thanks...
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