Hello I am a highschool student, Amanda, ready to take my SAT's and I always have trouble figuring out this problem...What is the easiest way to solve it?

The circumference of a larger circle is twice the circumference of a smaller circle. What is the ratio of the radius of the smaller circle to the diameter of the larger circle?

A devoted student..

Hi Amanda,

Suppose that the smaller circle has radius r, the larger circle has radius R and the larger circle has diameter D. You are looking for the ratio of r to D, or said as a fraction, the fraction ^r/_D.

The circumference of a circle is 2 (the radius) and hence the statement "The circumference of a larger circle is twice the circumference of a smaller circle." is

2 R = 2(2 r)

What is  ^r/_D?

Penny