A pipe with a diameter of two centimeters can fill a tank through constant flow of water in 1½ hours. The new pipe with a diameter of 6 centimeters can fill it in
(a) 30 minutes (b) 20 minutes (c) 15 minutes (d) 10 minutes

• Area=Pie*(D/2)^2
  for 2 cm dia pipe,
  Area=Pie*(2/2)^2=Pie
  
  for 6 cm dia pipe,
  Area=Pie*(6/2)^2=Pie*9
  
  If time taken in 2 cm dia pipe =1&1/2=90 mins,then in 6cm dia pipe the time will taken =(90/9)=10 mins.
  
  Ans. 10 mins.
• 13 years agoHelpfull: Yes(13) No(6)
• {(22/7)*1*1*1.5}={(22/7)*1*1*T)
  there fore T = 1/6 hrs
  T = 10 min
  Hence D is correct option
• 13 years agoHelpfull: Yes(4) No(4)
• its like
  volume filled by p1= volume filled by p2
  => (pi*r1^2)*t1=(pi*r2^2)*t2
  t1=9*t2;
  (3/(9*2))=t2;
  =>t2=(1/6)hrs;
  =>t2=(60/6)mins
  =>t2= 10min
• 8 years agoHelpfull: Yes(1) No(0)