Ruby red paint costs $0.50 per square inch. A ball is painted ruby red and costs $100.00 to paint. What is the diameter of the ball? Round to the nearest tenth of an inch ... A. 4.0 in ... B. 5.6 in ... C. 8.0 in ... D. 16.0 in.

The diameter can be obtained by the formula A = pi*r^2

First, multiply 0.50 * 100 to obtain the area of the ball, then simplify and solve for the radius. Doubling the radius would yield the diameter. This is shown below:

Area of the ball = 0.50 * 100 = 50 in^2

A = pi*r^2

50 = (3.14) * r^2

r = 3.99 = approx. 4

diameter = 2r

Diameter = 8 inches.

Among the choices, the correct answer is C. 8.0 in.