A man in a train travelling at 25km/hr notices that a train going in the opposite direction passes him in 7 sec.If the length of this train is 180m find its speed . Choose the correct answer:  A) 30 km/hr  B) 40 km/hr  C) 50 km/hr  D) 68 km/hr  E) 70 km/hr
relative speed of trains = 180/7 mtrs/sec = 180*18/(7*5)= 93 km/hr   speed of 2nd train = 93-25= 
<gadget id="calculator">93-25</gadget>
<output>68</output>
68 km/hr   ANSWER:68 km/hr
<result>D</result>
A man in a train travelling at 25km/hr notices that a train going in the opposite direction passes him in 7 sec.If the length of this train is 180m find its speed .