In a particular city, the sales potential of a single product from for five consecutive days are 100, 90, 95, 105, 110 units, respectively, at a price of 100 per unit. The cost of bringing the product to the market (customer) is 80 per unit. Left over stock of each day is cleared at a price of 50per unit. The firms starts each day with a stock of 100 units. The mark down loss for the five - day period is equal to. (750)