Economical order quantity(Numerical) ll Discount or Price break

A shopkeeper estimates the annual requirement of an item as 2000 units. He buys it from his supplier at a cost of Rs 10 per item and the cost of ordering is Rs 50 each time he orders. If the stock holding costs are 25 percent year of stock value, how frequently should he replenish his stocks.?
Further, suppose the supplier offers a 10 percent discount on orders between 400 and 699 items, and a 20% discount on orders exceeding or equal to 700. Can the shopkeeper reduce his costs by taking advantage of either of these discounts?