A and B are two cities. A man travels from A to B at 35 km/ hr and returns at the rate of 15 km/hr. Find his average speed for the whole journey?A20 km/hrB21 km/hrC22.5 km/hrD22 km/hrAnswer: B. 21 km/hr Read Explanation: 2xy/(x+y) = (2 x 35 x 15) / (35+15) = (2 x 35 x 15) / 50 = 21 km/hrRead more in App