concrete forming tubes are used as molds for cylindrical concrete supports. The volume V of a tube is the product of it's length l and area A of its circular base. You can make 2/3 ft^3 of cement per bag. Write a rule to find the number of bags of cement needed to fill a tube 4ft long as a function of its radius r. How many bags are needed to fill a tube with a 4-in. radius? a 5-in. radius? A 6-in. radius?

Question

anonymous · Answer

Start by writing out the formula. Then fill in the known numbers.