Carlos is fertilizing his garden. the garden is in the shape of a rectangle. its length is 15 feet and its width is 12 feet. suppose each bag of fertilizer covers 20 square feet. how many bags will he need to cover the garden?

The area of the garden is
.. area = length * width
.. = (15 ft)*(12 ft)
.. = 180 ft^2

Then the number of bags can be computed from
.. 180 ft^2 = (20 ft^2) * (number of bags)
.. (180 ft^2)/(20 ft^2) = (number of bags)
.. 9 = (number of bags)

9 bags of fertilizer are needed to cover the garden.