Aptitude - Problems on Trains - Discussion
Discussion Forum : Problems on Trains - General Questions (Q.No. 16)
16.
A train travelling at a speed of 75 mph enters a tunnel 3
miles long. The train is 
mile long. How long does it take for the train to pass through the tunnel from the moment the front enters to the moment the rear emerges?
miles long. The train is mile long. How long does it take for the train to pass through the tunnel from the moment the front enters to the moment the rear emerges?Answer: Option
Explanation:
| Total distance covered |
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 Time taken |
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| = 3 min. |
Discussion:
129 comments Page 2 of 13.
Naren said:
6 years ago
Hey guys, don't much obsessed with it. It's quite simple as it is.
1 mile=1.609 km.
Distance travelled by train = (7/2+1/4) only.
For easy understanding.
Assume that you are standing at the tunnel starting end with a stopwatch and now the train is coming and (note that in the question he said that from the front end entres) that means when the engine comes to the position where you are standing then you start the stopwatch from that point, the train goes on goes on and after some time the engine part reaches to the exit end of the tunnel and (note that in the question he said time should be calculated till the rear emerges) so don't stop the stopwatch let the train go and the strain is going going going and after some time the last bhogi (last part) of the train left the tunnel then you need to stop the stopwatch.
Then note the time. So that time is only required.
Observe carefully in this entire process the train is travelling only the tunnel length and its own length.
And coming to question.
The question is error instead of metres he has given miles.
So don't bother much about this.
If you guys have any doubt about the above explanation just take a pen and paper and draw a line and observe the above explanation. Then You guys get that.
I hope you understand.
Have a nice day.
1 mile=1.609 km.
Distance travelled by train = (7/2+1/4) only.
For easy understanding.
Assume that you are standing at the tunnel starting end with a stopwatch and now the train is coming and (note that in the question he said that from the front end entres) that means when the engine comes to the position where you are standing then you start the stopwatch from that point, the train goes on goes on and after some time the engine part reaches to the exit end of the tunnel and (note that in the question he said time should be calculated till the rear emerges) so don't stop the stopwatch let the train go and the strain is going going going and after some time the last bhogi (last part) of the train left the tunnel then you need to stop the stopwatch.
Then note the time. So that time is only required.
Observe carefully in this entire process the train is travelling only the tunnel length and its own length.
And coming to question.
The question is error instead of metres he has given miles.
So don't bother much about this.
If you guys have any doubt about the above explanation just take a pen and paper and draw a line and observe the above explanation. Then You guys get that.
I hope you understand.
Have a nice day.
(3)
Sravya Sree said:
2 years ago
@Atikraja.
It is a mixed fraction.
First, multiply 2(denominator)*3(first term numerator) = 6 then add 1 which is 7 and include the denominator as it is;
i.e 3*2+1=7/2.
It is a mixed fraction.
First, multiply 2(denominator)*3(first term numerator) = 6 then add 1 which is 7 and include the denominator as it is;
i.e 3*2+1=7/2.
(2)
Muthumari said:
2 years ago
Speed = distance/time.
75/60(meter/min) = [ (7/2)+(1/4)] ÷ t.
t = (15/4)×(60/75),
t = 3min.
75/60(meter/min) = [ (7/2)+(1/4)] ÷ t.
t = (15/4)×(60/75),
t = 3min.
(2)
Arbino said:
4 years ago
@All.
In question it is clearly mentioned that the rear part of the train got emerge in the tunnel, so we have to calculate the only the length of the train which is 1/4mile.
Correct me, if I am wrong.
In question it is clearly mentioned that the rear part of the train got emerge in the tunnel, so we have to calculate the only the length of the train which is 1/4mile.
Correct me, if I am wrong.
(1)
Suriya said:
8 months ago
@All.
Just add the distance, simply using the time formula. You get 0.05 hours just multiply 60 to get minutes. The answer is 3.
Just add the distance, simply using the time formula. You get 0.05 hours just multiply 60 to get minutes. The answer is 3.
(1)
Sharan said:
2 decades ago
1mile=?km
Sundar said:
2 decades ago
1 mile = 1.60934 km.
Ghousia said:
2 decades ago
How 15/(4*75) hrs?
Deepti said:
1 decade ago
Time = Distance/ Dpeed.
Speed= 75 mph, distance= 15/4.
Speed= 75 mph, distance= 15/4.
ERRER said:
1 decade ago
Explain how 7/2?
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