A man in a train travelling at 30km/hr notices that a train going in the opposite direction passes him in 9 sec.If the length of this train is 200m find its speed . Choose the correct choice from the following:
A) 30 km/hr B) 40 km/hr C) 50 km/hr D) 60 km/hr E) 70 km/hr
relative speed of trains = 200/9 mtrs/sec = 200*18/(9*5)= 
<gadget id="calculator">200*18/(9*5)</gadget>
<output>80</output>
80 km/hr   speed of 2nd train= 80-30= 
<gadget id="calculator">80-30</gadget>
<output>50</output>
50 km/hr   ANSWER:50 km/hr
<result>C</result>
A man in a train travelling at 30km/hr notices that a train going in the opposite direction passes him in 9 sec.If the length of this train is 200m find its speed .