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.
GURAVAREDDY said:
7 years ago
Given data is D1=3(1/2), D2=1/4 S=75m/s.
respective length is (7/2+1/4)=15/4,
S=D/T.
75=(15/4)/T,
T=(15/4)/(1/75),
=15/4*75,
=1/20.
SO ITS IN SEC.
CONVERT INTO HRS.
= (1/20)*60.
= 3 MINS.
respective length is (7/2+1/4)=15/4,
S=D/T.
75=(15/4)/T,
T=(15/4)/(1/75),
=15/4*75,
=1/20.
SO ITS IN SEC.
CONVERT INTO HRS.
= (1/20)*60.
= 3 MINS.
Nutan said:
7 years ago
7/2 + 1/4 = 15/4 how it comes? Please explain someone.
Sarang said:
7 years ago
Distance=speed * time.
3.1/2+1/4=75 m/h *time,
3.5+.25=75m/h*time,
3.75=75m/h *time,
3.75/75m/h=time,
Time=.05*60=3min.
3.1/2+1/4=75 m/h *time,
3.5+.25=75m/h*time,
3.75=75m/h *time,
3.75/75m/h=time,
Time=.05*60=3min.
Bharath said:
7 years ago
The answer is C.
~Banu said:
7 years ago
Why put 7/2 In total distance covered?
S.D.Brite said:
8 years ago
@Ashu.
They ask only for the time to cross the tunnel...
The train is driven by the engine, which is in the front part of the train.
;So we need to calculate the distance as;
7/2 mile + 1/4 mile = 3.75 mile.
They ask only for the time to cross the tunnel...
The train is driven by the engine, which is in the front part of the train.
;So we need to calculate the distance as;
7/2 mile + 1/4 mile = 3.75 mile.
Ashu said:
8 years ago
We must add two times the distance of the train because we are just calculating the time needed to cross the tunnel if we just add one time the length of the train. So the answer must be 3.2min.
It doesn't need to explain the question that if we add only one time.
It doesn't need to explain the question that if we add only one time.
Tushar V. Ladukar said:
8 years ago
In the question as length of the tunnel is mentioned 3 miles and length of train 1 miles, how 7/2 and 1/4 is taken respectively?
Varsha said:
8 years ago
How 15/4*75 hrs?
Sathish said:
8 years ago
Distance/speed = time.
So.
15/4 * 75 means it comes (15/4) /75 so 15*75/4 is the way is correct why 15/4*75? Explain.
So.
15/4 * 75 means it comes (15/4) /75 so 15*75/4 is the way is correct why 15/4*75? Explain.
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