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
