A motorist travels to a place 150 km away at an average speed of 50 km/hr and returns at 30 km/hr. His average speed for the whole journey in km/hr is ?  Options:
A) 37.9	B) 37.53	C) 37.5	D) 37.1	E) 37.4
Explanation:   Average speed = (2xy) /(x + y) km/hr   = (2 * 50 * 30) / (50 + 30) km/hr.   37.5 km/hr.   Answer: 37.5
<result>C</result>
A motorist travels to a place 150 km away at an average speed of 50 km/hr and returns at 30 km/hr. His average speed for the whole journey in km/hr is ?