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 metres) is :
Pick
A) 130	B) 360	C) 500	D) 540	E) 650
Explanation:   Speed = (78 *5/18)m/sec =65/3m/sec   Time = 1 minute = 60 sec.   Let the length of the tunnel be x metres.   Then,800+X/60=65/3   =&gt; 3 (800 + x) = 3900 =&gt;X=500.   ANSWER IS 500
<result>C</result>
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 metres) is :