A manufacturer has to supply to his customer 600 units of his product per year. Storage is not allowed and the inventory–carrying costs amount to Rs. 0.60 per unit per year. The set–up cost per run is Rs. 80.

Find:

(i) The economic order quantity

(ii) The minimum average yearly cost

(iii) The optimum number of orders per year

(iv) The optimum period of supply per optimum order.