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 |
|
|||||||||
|
 Time taken |
|
|||||||
|
||||||||
|
||||||||
| = 3 min. |
Discussion:
129 comments Page 7 of 13.
Appa rao said:
9 years ago
The answer should be option C.
Total distance covered = 7/2(tunnel) + 1/4(length of train) + 1/4(length of train since the rear part is to be considered emerging) = 4 miles.
So total time taken = (4 miles/75mph ) * 60 mins.
= 3.2 mins.
So the answer is option C.
Total distance covered = 7/2(tunnel) + 1/4(length of train) + 1/4(length of train since the rear part is to be considered emerging) = 4 miles.
So total time taken = (4 miles/75mph ) * 60 mins.
= 3.2 mins.
So the answer is option C.
Raju Ahmed said:
9 years ago
Total distance covered = 7/2(tunnel) + 1/4(length of train) + 1/4(length of train since the rear part is to be considered emerging) = 4 miles.
So total time taken = (4 miles/75mph ) * 60 mins.
= 3.2 mins.
So the answer is [C].
So total time taken = (4 miles/75mph ) * 60 mins.
= 3.2 mins.
So the answer is [C].
Abi said:
9 years ago
Why finally it convert into hours? Please explain.
Nivin said:
9 years ago
I agree with you @Sanjay Singh.
Prakhar Mittal said:
9 years ago
It is not clear that the speed is given in which units as Rahul Bhosale asked above.
Sanjay singh said:
9 years ago
According to me, the answer is 3.2 min.
Kunal hire said:
9 years ago
How to convert min into an hour? Please anyone explain.
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.
Rahul Bhosale said:
9 years ago
Mph means mile per hour OR meter per hour?
I think mile per hour is correct.
I think mile per hour is correct.
Anup said:
9 years ago
Let me try to make this clear in 2 points.
#1. This question is same as train crossing the platform
#2. If we keep on reducing the size of tunnel till it reaches to size zero,i.e., the tunnel has now become a point so now we will calculate the time by using the length of the train only once. now when the size of the tunnel is added we can calculate time by Length of the train + Length of the tunnel / speed of the train.
#1. This question is same as train crossing the platform
#2. If we keep on reducing the size of tunnel till it reaches to size zero,i.e., the tunnel has now become a point so now we will calculate the time by using the length of the train only once. now when the size of the tunnel is added we can calculate time by Length of the train + Length of the tunnel / speed of the train.
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers