If a car travels from A to B at an average speed of 50 km/hour. At what average speed would it have to travel from B to A to average 60 km/hour for the whole trip?

• 75 km/h have to travel from B to A
  Speed from A--->B x=50
  we find out B--->A.y=? so
  The Average speed =2xy/(x+y)=60
  2*50*y/50+y=60
  100y=3000+60y
  40y=3000
  so y=75km/hr
• 12 years agoHelpfull: Yes(5) No(3)
• 70km/hour have to travel from B to A.
  
  Travel from A to B, X = 50km/hour.
  Travel from B to A, Y = ??
  
  Average Speed :
  X+Y /2 = 60km/hour
  X + Y = 60km/hour * 2
  X + Y = 120km/hour
  We already know X= 50km/hour. Apply it.
  
  50km/hour + Y = 120km/hour
  Y = 120km/hour - 50km/hour
  Y = 70km/hour.
  
  So, Car have to travel 70km/hour from B to A to average 60 km/hour for the whole trip.
• 12 years agoHelpfull: Yes(4) No(2)
• 70km/hour have to travel from B to A.
  
  Travel from A to B, X = 50km/hour.
  Travel from B to A, Y = ??
  
  Average Speed :
  X + Y /2 = 60
  X + Y = 60 * 2
  X + Y = 120
  
  We already know X = 50km/hour. Apply it.
  50 + Y = 120
  Y = 120 - 50
  Y = 70km/hour.
  
  So, Car have to travel 70km/hour from B to A to average 60 km/hour for the whole trip.
• 12 years agoHelpfull: Yes(2) No(1)