The demand for a certain product is 6,000 units per year. The fixed administrative cost of placing an order is Rs.1,000 and the stock holding cost is Rs.30 per unit per year. Discount is available and the discount rate is as follows:

Up to 999th cost Rs.15 per unit

1000th to 2999th cost Rs.14.60 per unit

3000th to over cost Rs.14.20 per unit

Taking the advantage of the discount offer, calculate the

i.) Economic lot size.

ii.) Corresponding average yearly cost.