Jeffrey is buying mulch for a circular flower garden with a diameter of 12 feet. the layer of mulch needs to be 4 inches thick. what is the volume of mulch needed for the flower garden?

This will end up being a cylinder, and the formula for the volume of a cylinder is:



We are told the diameter, and the height.  We can covert the diameter into the radius by dividing it by two.  So, the radius of the garden is 6 feet.

Next, we need to convert the units.  We can either convert the radius to inches, or the height to feet.  I will choose to convert the height to feet.  You convert inches to feet by dividing the number by 12.

4/12=0.333.  Now, we have all the information necessary to put it in the formula.



So, the answer is 37.70 cubic feet.