A circular swimming pool is surrounded by a concrete wall 4ft wide. If the area of the wall is 11/25 of the area of the pool then radius of the pool in feet is
a) 20
b) 8
C) 16
d) 30

• i thnk ans is 20.Bcoz let r be the radius of pool.
  (11/25)(pi*r^2)=(pi(r+4)^2)-(pi*r^2)
  By solving this we get ans as 20
• 11 years agoHelpfull: Yes(25) No(0)
• a) 20 ft.
  If radius of pool=r ,wall thickness=4 ft.
  I) Area of the pool= Pi*r^2
  II) Area of the wall=Pi(r+4)^2-Pi*r^2= Pi*8(r+2)
  Given Pi*8(r+2)=11/25[Pi*r^2]
  11r^2-200r-400=0
  (11r+20)(r-20)=0, r=20
• 11 years agoHelpfull: Yes(20) No(0)
• pi(r+4)^2 - pi(r^2)=11/25(pi(r^2)
  so r=20
• 11 years agoHelpfull: Yes(4) No(0)
• here ans wil be 20
  
• 11 years agoHelpfull: Yes(2) No(2)
• ans is 50
  
• 8 years agoHelpfull: Yes(0) No(4)