1953 AHSME Problems/Problem 12
Problem
The diameters of two circles are inches and
inches respectively. The ratio of the area of the smaller to the area of the larger circle is:
Solution
The area of a circle can be calculated as where
is the radius. We know that the radii of the circles are
and
inches (half the diameter) so the ratio of the area of the smaller to the area of the larger circle is
.