The circles shown continue infinitely and have diameters 16 inches, 8 inches, 4 inches, and so on. The diameter of each circle is half the diameter of the previous circle. What is the number of square inches in the sum of the areas of all circles? Express your answer to the nearest whole number.
Area sequence pi (64 + 16 +4 + 1) the common ratio is 1/4 as you can see
sum of an infinite sequence
S = a1 / (1-r)
64 pi / (1 - 1/4 ) = 85.33 pi in2
...did you multiply by the 'pi' before you just took and ran with the numerical answer?