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A train 800 metres long is running at a speed of 78 km/hr

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.130B.360
C.500D.540

Answer: Option C
Explanation:
Speed =(78 x5(m/sec=(65(m/sec.
183
Time = 1 minute = 60 seconds.
Let the length of the tunnel be x metres.
Then,(800 + x(=65
603
=> 3(800 + x) = 3900
=> x = 500.

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