John wants to put a circular garden in his back yard. The garden has a diameter of 16 feet. He needs to cover the garden with peat moss. Each bag of peat moss can cover 90 square feet. How many bags does he need?

Answer 1

The area of John's back yard garden will be A = pi*r^2 where r = radius = 1/2 the diameter.
Then set up a proportion as follows:
(1 bag/90 ft^2)=(x bags/area garden)
solve for x bags. The answer I obtained is 2.23 bags; therefore, John must buy 3 bags.