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 5 of 13.
Sudheer said:
1 decade ago
Given data is
Distance is (7/2 ) + (1/4 ) = (15/4)
Speed is 75mph
Formula for this is speed=(length/time) i.e.,Time=(length/speed)
Time=(15/4)/75=(15/(4*75))=3 mins
Distance is (7/2 ) + (1/4 ) = (15/4)
Speed is 75mph
Formula for this is speed=(length/time) i.e.,Time=(length/speed)
Time=(15/4)/75=(15/(4*75))=3 mins
Shro said:
1 decade ago
As per the given question:
tunnel's length is 3(1/2) i.e. = 7/2
train's length is 1/4.
So as per the formulas we are supposed to add lengths so we add (7/2)+(1/4)
tunnel's length is 3(1/2) i.e. = 7/2
train's length is 1/4.
So as per the formulas we are supposed to add lengths so we add (7/2)+(1/4)
Shro said:
1 decade ago
Guys for those who asked doubt here is the answer.
Its given in miles per hour and we have to find time in minutes.
So no need to convert into any other form.
Its given in miles per hour and we have to find time in minutes.
So no need to convert into any other form.
GSC said:
1 decade ago
Its 7/2 + 1/4 + 1/4 miles as the distance of the train has to be counted twice (in the question it says, the rear has to come out). That makes it 3.2 mins.
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.
Manni said:
1 decade ago
It will be 3mins.
Because total distance is 7/2 (tunnel) +1/4 (train).
When train starts entering tunnel there is nothing inside so why take 2 times.
Because total distance is 7/2 (tunnel) +1/4 (train).
When train starts entering tunnel there is nothing inside so why take 2 times.
Akshay said:
1 decade ago
Everyone saying that the length of the train has to be added twice is right because really we are asked about the moment REAR EMERGES, not THE FRONT.
Avii said:
9 years ago
Yeah! the answer will be 3.2 sec.
As it is clearly written from the moment front enter to the moment rear emerge so, twice the length of the train.
As it is clearly written from the moment front enter to the moment rear emerge so, twice the length of the train.
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)
Harish said:
2 years ago
Train distance is in miles and speed is in meters without conversion of miles into meters how can we compare both?
Anyone, please clarify this.
Anyone, please clarify this.
(14)
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