(a) 45 km/hr
(b) 50 km/hr
(c) 54 km/hr
(d) 55 km/hr
Explanation:
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 x km/hr. Then, relative speed = (x – 5) km/hr.
x – 5 = 45
x = 45+5
x = 50 km/hr.