Scaling Circles

The area of circle \(A\) is \(25\pi\), and the area of circle \(B\) is \(4\pi\). What is ratio of the circumference of circle \(A\) to the circumference of circle \(B\).

(A) 2.5 : 1      (B) 5 : 2      (C) 5 : 4    (D) 25 : 16      (E) 125 : 1 Read more ›