A company orders gears in conditions identical to those considered in the economic order quantity (EOQ) model in inventory control. The annual demand is 8000 gears, the cost per order is 300 rupees, and the holding cost is 12 rupees per month per gear. The company uses an order size that is 25% more than the optimal order quantity determined by the EOQ model. The percentage change in the total cost of ordering and holding inventory from that associated with the optimal order quantity is

The order processing charges are Rs. $$500$$/order. The handling plus carry-over charge on an annual basis is $$20\% $$ of the purchase price of the corn flour per $$kg$$. The optimal order quantity (in $$kg$$) is __________.