Question: 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:
[A].130
360
500
540
[A].
[B].
[C].
[D].
Answer: Option C
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.