A cylindrical can holds 400cm^3 of liquid. The cost of material for the circular top and bottom of the can is 3 cents per square centimeter and the cost of material for the curved sides is 2 cents per square centimeter. Find two equations for the cost C in terms of...

a) the radius of the top and bottom

b) the height of the can h

soo i know v= (pi)r^2(h) but i don't know how that helps me at all in this problem!