The volume of paint used, V liters, is directly proportional to the area, A square feet, that the paint can cover. 5 liters of paint can cover a wall with an area of 75 square feet. a) What is the constant of proportionality? Tell how you found it.

b) Write an equation relating V and A.

c) How much paint would be needed to cover an area of 180 square feet? Show your work.