Peppy Quadcopters plans to sell a standard quadcopter (toy drone) for $ 40 and a deluxe quadcopter for $ 50. Peppy purchases the standard quadcopter for $ 20 and the deluxe quadcopter for $ 30. Management expects to sell two deluxe quadcopters for every three standard quadcopters. The company's monthly fixed expenses are $ 14 comma 000. How many of each type of quadcopter must Peppy sell monthly to breakeven? To earn $ 15 comma 000?

First identify the formula to compute the sales in units at various levels of operating income using the contribution margin approach. (Abbreviations used: Avg. = average, and CM = contribution margin.)