AMC 8 2008 Problem 25
Source:
July 22, 2011
percentgeometry
Problem Statement
Margie's winning art design is shown. The smallest circle has radius 2 inches, with each successive circle's radius increasing by 2 inches. Approximately what percent of the design is black?[asy]
real d=320;
pair O=origin;
pair P=O+8*dir(d);
pair A0 = origin;
pair A1 = O+1*dir(d);
pair A2 = O+2*dir(d);
pair A3 = O+3*dir(d);
pair A4 = O+4*dir(d);
pair A5 = O+5*dir(d);
filldraw(Circle(A0, 6), white, black);
filldraw(circle(A1, 5), black, black);
filldraw(circle(A2, 4), white, black);
filldraw(circle(A3, 3), black, black);
filldraw(circle(A4, 2), white, black);
filldraw(circle(A5, 1), black, black);
[/asy]