Megha drives along the perimeter of square field of side 10 kms. She drives along the first side at 10 kmph, along the second side at 20 kmph, along the third side at 30 kmph and along the fourth side at 40 kmph. Her average speed is

• avg speed = total distance / total time = 4d / (d/10 + d/20 + d/30 + d/40) where d = 10 km
  
  = 4 / (1/10 + 1/20 + 1/30 + 1/40) = 4 * 120/25 = 19.2 km/h
  
• 9 years agoHelpfull: Yes(21) No(0)