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.
Shubham said:
4 years ago
Ans must be 3.2 min.
We have to take the length of train twice.
7/2 + 1/4 + 1/4 = 4 miles.
Then,
Time = 4/75.
=0.05333 hr.
In seconds 0.05333*60= 3.198 which is 3.2 min.
We have to take the length of train twice.
7/2 + 1/4 + 1/4 = 4 miles.
Then,
Time = 4/75.
=0.05333 hr.
In seconds 0.05333*60= 3.198 which is 3.2 min.
(23)
Kishan Maurya said:
4 years ago
Length of train will be 2 times of 1/4.
And correct ansr is 3.2min.
And correct ansr is 3.2min.
(6)
Arbaj Tamboli said:
4 years ago
75 mph means 75 miles per hour.
(5)
Arbaj Tamboli said:
4 years ago
75 mph is nothing, it's 75 miles per hour.
Asli_hai said:
4 years ago
The question says front contact and back part emerges out that means the length of tunnel + 2 times length of the train.
So the answer will be 3.2.
So the answer will be 3.2.
(5)
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)
Balakiruthiga Subramanian said:
4 years ago
I think only the length of the tunnel must be considered because only the time taken for the front part to re-emerge is asked.
Correct me, if I am wrong.
Correct me, if I am wrong.
Veda said:
5 years ago
@Palla Nagesh.
7/2+1/4 = 14 + 1/4.
Take LCM for 2 & 4 then final lcm is 4.
Because we write 4 at denominator then 2*2=4 2*7=14 4*1=4
And finally, we get the ans 15/2.
7/2+1/4 = 14 + 1/4.
Take LCM for 2 & 4 then final lcm is 4.
Because we write 4 at denominator then 2*2=4 2*7=14 4*1=4
And finally, we get the ans 15/2.
PALLA NAGESH said:
5 years ago
(7/2+1/4) = (28+2)/4 = 30/4 = 15/2 , but how you will tell its as 15/4?
Can you explain it clearly?
Can you explain it clearly?
Shimul Khalid said:
5 years ago
Distant: 7/2+1/4+1/4 miles = 4 miles.
Speed: 5/4 miles/minute.
Time duration should be 3.2 minutes, I think.
Speed: 5/4 miles/minute.
Time duration should be 3.2 minutes, I think.
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