A train 125 m long passes a man, running at 5 km/hr in the same direction in which the train is going, in 10 sec. The speed of the train is? Choose one:  A) 40  B) 50  C) 60  D) 79  E) 80
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 - 5) km/hr.   x - 5 = 45 =&gt; x = 50 km/hr.   Answer: Option 50
<result>B</result>
A train 125 m long passes a man, running at 5 km/hr in the same direction in which the train is going, in 10 sec. The speed of the train is?