There are two concentric circles with radii 8 and 6. If the radius of the outer circle is increased by 25% and the radius of the inner circle decreased by 50%, by what percent does the area between the circles increase?	Choose the correct choice from the following choices:
A) 225
B) 250
C) 275
D) 300
E) 325

Rationale: "the area of a circle is pir ^ 2 , where r is the radius . the area of the big circle is 64 pi . the area of the small circle is 36 pi . the area a 1 between the circles is 28 pi . when the big circle ' s radius increases , the new area is 100 pi . when the small circle ' s radius decreases , the new area is 9 pi . the area a 2 between the circles is 91 pi . the ratio of a 2 / a 1 is 91 / 28 = 3.25 which is an increase of 225 % . the answer is a ."
Answer: A