A circular swimming pool is surrounded by a concrete wall 4 feet wide.if the area of the wall is 11/25 of the area of the pool, then the radius of the pool in feet is? Choose the correct choice from the following answers.
A) 22	B) 88	C) 37	D) 20	E) 289
Let the radius of the pool be r. Then area of the wall and pool = π(r+4)2π(r+4)2   Area of the pool = π(r)2π(r)2   Area of the wall = π(r+4)2−π(r)2π(r+4)2−π(r)2   Given π(r+4)2−π(r)2π(r+4)2−π(r)2 = 1125(πr2)1125(πr2)   r2+8r+16−r2=1125r2r2+8r+16−r2=1125r2   11r2−200r−400=011r2−200r−400=0   Solving r = 20   Answer:20
<result>D</result>
A circular swimming pool is surrounded by a concrete wall 4 feet wide.if the area of the wall is 11/25 of the area of the pool, then the radius of the pool in feet is?