3. From the following details, prepare an estimate of the requirement of Working Capital:

Production 60,000 units Selling price per unit `5 Raw materials 60% of selling price Direct Labour 10% of selling price Overheads 20% of selling price Materials in hand 2 months Production time 1 month Finished goods in stores 3 months Credit for materials 2 months Credit allowed to customers 3 months Average cash balance `20,000 Wages and overheads are paid at the beginning of the month following. In production, all the required materials are charged in the initial stage and wages and overheads accrue evenly.