A company manufactures a single product having a Marginal Cost of Re. 0.75 a unit. Fixed Costs are Rs. 12,000. The market is such that up to 40,000 units can be sold at Rs. 1.50 a unit, but any additional sales must be made at Re. 1 a unit only. There is a planned profit of Rs. 20,000. How many units to be made and sold?