On a journey, across Delhi, a Taxi averages 30 kmph for 60% of the distance, 20 kmph for 20% of it and 10kmph for the remainder. The average speed for the whole journey is :
a)20
)22.5
c)25
d)24.625
e)26

• 20
  
  If total distance is 100 kms,
  
  60 kms is covered in 60/30=2 hrs
  20 kms is covered in 20/20=1 hrs
  rest 20 kms distance is covered in 20/10= 2 hrs
  total time taken = 2+1+2= 5 hrs
  average speed = 100/5 = 20 kmph
• 11 years agoHelpfull: Yes(7) No(1)
• avg speed = total distance travelled / total time taken
  
  Total distance = d
  total time taken = t1 + t2 + t3
  
  t1 = d1 / s1 = d / 50
  t2 = d2 / s2 = d/100
  t3 = d3 / s3 = d / 50
  
  => avg speed = d / [ (d/50) + (d/100) + (d/50) ]
  = 20 kmph
• 11 years agoHelpfull: Yes(1) No(1)
• Let D be distance
  Average speed= totaldistance/time taken
  =d/((60d/100*30)+(20d/100*20)+(20d/100*10))
  =20
• 8 years agoHelpfull: Yes(0) No(0)