A train 125 m long passes a man, running at 10 km/hr in the same direction in which the train is going, in 10 sec. The speed of the train is?  Choose the most appropriate option:
A) 65 km/hr
B) 17 km/hr
C) 55 km/hr
D) 50 km/hr
E) 15 km/hr
Speed of the train relative to man = 125/10 = 25/2 m/sec.   = 25/2 * 18/5= 
<gadget id="calculator">25/2 * 18/5</gadget>
<output>45</output>
45 km/hr   Let the speed of the train be x km/hr. Then, relative speed= (x - 10) km/hr.   x - 10 = 45 =&gt; x = 55 km/hr.   Answer: 55 km/hr
<result>C</result>
A train 125 m long passes a man, running at 10 km/hr in the same direction in which the train is going, in 10 sec. The speed of the train is?