A tank is formed by adjoining two hemispheres to the ends of a right circular cylinder. The volume of the tank must be 4000 ft³. The material for the hemispherical ends costs 2/ft² while the material for the cylindrical sides costs1/ft². What is the total cost of the materials used to construct the tank?
1) $8000
2) $6000
3) $4000
4) $2000
