There is a pool of radius X and there is a path way around the pool with a width of 4 feet. Find the radius of the pool if the path area / pool area = 11/25

Option
a) 12
b) 5
c) 25
d) 29

• (PI.(X+4)^2-PI.X^2)/PI.X^2=11/25
  (X+4)^2/X^2-1=11/25
  (X+4)^2/X^2=36/25
  (X+4)/X=6/5
  X=20
  
• 11 years agoHelpfull: Yes(46) No(3)
• its just a dummy ques ... as unit of pool's radius is not mentioned so you can equate it with "feet"......... asked in tcs in some colleges of south.. :)
  
  
• 11 years agoHelpfull: Yes(6) No(8)
• Let pool radius=r
  pi*(x+4)^2 - pi*r^2=pi*r^2 * 11/25
  x=20
  so radius of pool=20 feet.
• 11 years agoHelpfull: Yes(3) No(0)
• (r+4)^2 - r^2 /r^2 =11/25
  (r+4)^2 /r^2 = 11/25 +1
  ((r+4)/r)^2 = 36/25
  (r+4) / r = sqrt(36 /25 )
  (r+ 4) / r =6 /5
  5r + 20 = 6r
  r =20
• 8 years agoHelpfull: Yes(3) No(0)
• pi(x+4)^2-pix^2/pix^2=11/25
  solve x
• 11 years agoHelpfull: Yes(1) No(2)
• ans is 20,which is not given above..
  
• 11 years agoHelpfull: Yes(1) No(0)
• bnate bnate haalt khrab ho gya answer 20feet nikala tha..
  fir v solve dubara se bnate ja rhe the..niche dekha tb pta chla ki option hi glt dala gya h.. so guys please update question with correct options...
  
• 11 years agoHelpfull: Yes(1) No(1)
• Ans 20
  (pi(X+4)^2-pi(X)^2)/pi(X)^2=11/25
  on solving we get x=20
• 11 years agoHelpfull: Yes(1) No(0)
• ans is 25
  
• 9 years agoHelpfull: Yes(1) No(2)
• ans [pi{(x+4)^-x^2}]/pi x^2=11/25
  then solving we get x=20 feet
• 11 years agoHelpfull: Yes(0) No(0)
• ans is (a)12
• 11 years agoHelpfull: Yes(0) No(7)
• x=20 which is not given in options :p
• 11 years agoHelpfull: Yes(0) No(1)
• [pi{(x+4)^-x^2}]/pi x^2=11/25
  so x = 20
• 11 years agoHelpfull: Yes(0) No(2)
• X=20
• 11 years agoHelpfull: Yes(0) No(0)
• yes 20 is the correct
  
• 11 years agoHelpfull: Yes(0) No(0)