A good 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:
Choices: A) 600 B) 300 C) 400 D) 500 E) 200
speed = 78*5/18 m/sec ==&gt;65/3   length of the tunnel be x   then 800+x/60 = 65/3   3(800+x) = 3900   x=500   ANSWER 500
<result>D</result>
A good 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: