How much of the area is preserved when you inscribe circles in circles

http://img30.imageshack.us/img30/282...lesproblem.png

What is the ratio of the area of the shaded portion in the figure on the right to the area of the shaded portion of the figure to the left? The circles are all tangent to each other even though the picture might not be exact. The inscribed circles in the left figure are congruent. The second figure is a result of inscribing 4 congruent circles in each of the 4 circles on the left.

I have no idea how to approach this. Thanks for taking the time to read my question!