Aptitude - Problems on Trains - Discussion
Discussion Forum : Problems on Trains - General Questions (Q.No. 17)
17.
A train 800 metres long is running at a speed of 78 km/hr. If it crosses a tunnel in 1 minute, then the length of the tunnel (in meters) is:
Answer: Option
Explanation:
| Speed = |  |
78 x | 5 |  |
m/sec | = | |
65 | |
m/sec. |
| 18 | 3 |
Time = 1 minute = 60 seconds.
Let the length of the tunnel be x metres.
| Then, | |
800 + x | |
= | 65 |
| 60 | 3 |
3(800 + x) = 3900
x = 500.
Discussion:
52 comments Page 6 of 6.
Sandeep kumar said:
10 years ago
It is simple- as a train covers 78 km in one hour so train covers 78000 meter (78*1000 meter) in 60 minuet, so train cover in one minutes is 78000/60=1300 meter train itself length 800 meter so tunnel length = total distance cover by train-train length, 1300-800 = 500 meter.
Parameshwar said:
10 years ago
May I know, how we got 5/18?
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