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...

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. Find the following:
a. Gross profit rate
b. Operating profit margin rate
c. Net profit margin rate
d. Return on Investment