11.4 What is the Cost? Circle A has a diameter of 20 inches. If rope costs $0.10 per inch, how much money does it cost to lay rope along the outside edge of the circle?

Circle B has a radius of 20 inches. If rope costs $0.05 per inch, how much money does it cost to lay rope along the outside edge of the circle?

A pool is the shape of a circle and has a diameter of 16 feet. A pool cover costs $1.50 per square foot. How much money would it cost to buy enough pool cover to cover the pool?