A man in a train travelling at 20km/hr notices that a train going in the opposite direction passes him in 5 sec.If the length of this train is 140m find its speed . Pick:	A) 30 km/hr	B) 40 km/hr	C) 81 km/hr	D) 60 km/hr	E) 70 km/hr
relative speed of trains = 140/5 mtrs/sec = 140*18/(5*5)= 101 km/hr   speed of 2nd train = 101-20= 
<gadget id="calculator">101-20</gadget>
<output>81</output>
81 km/hr   ANSWER:81 km/hr
<result>C</result>
A man in a train travelling at 20km/hr notices that a train going in the opposite direction passes him in 5 sec.If the length of this train is 140m find its speed .