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) 20	C) 9	D) 8	E) 1
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>B</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?