A Target consists of three concentric circles with the same center.

The radii of the circles have lengths of 3 inches, 7 inches and 9 inches.
The 7 inch radii spacing is shaded.
(To the nearest percent,)
What percent of the target is shaded?

1 answer

assuming you meant that the region between the 3" circle and the 7" circle is shaded,

(7^2-3^2)/9^2 = (49-9)/81 = 40/81 = 49%