A train of length 150 metres takes 40.5 seconds to cross a tunnel of length 300 metres. What is the speed of the train in km/hr?
Choose the correct choice:	A) 10 km/hr.	B) 20 km/hr.	C) 30 km/hr.	D) 40 km/hr.	E) None
Sol.   Speed = [150 + 300 / 40.5] m/sec = [450 / 40.5 * 18/5] km/hr = 40 km/hr.   Answer 40 km/hr.
<result>D</result>
A train of length 150 metres takes 40.5 seconds to cross a tunnel of length 300 metres. What is the speed of the train in km/hr?