A man travels at a speed of 6 km/hr for five hours and at a speed of 4 km/hr for 10 hours. His average speed is

 a) 5
 b) 4 ²/₃
 c) 4 ¹/₂
 d) 4 ¹/₃

LDC 2010-Malappuram

2/3. Solution Average speed = Total distance/Total time = (6x5) + (4x10) = 70km Total Time = 5+10 = 15 Average speed = 70/15 = 4 2/3