math
posted by Anonymous on .
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?

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.