A. 45 km/hr
B. 50 km/hr
C. 55 km/hr
D. 60 km/hr
Speed of the train relative to man = (125/10) m/sec
=> (25/2) m/sec
=> (25/2) x (18/5) km/hr
=> 45 km/hr
Let the speed of the train be z km/hr. Then, relative speed = (z - 5) km/hr
=> z - 5 = 45 z = 50 km/hr