Annie bought one dozen smartphones for P200,000.00 with a discount of 5%. She sold half dozen at a price of P18,000.00 per unit. However, a new model of smartphone became available in the market, so she sold the remaining half dozen @ P12,000.00 each unit. What was her profit or loss? Compute the following requirements: a. Gross profit rate b. Operating profit margin rate c. Net profit margin rate d. Return on Investment