Cruiseline offers nightly dinner cruises departing from several cities on the eastern coast of the United States including​ Charleston, Baltimore, and Alexandria. Dinner cruise tickets sell for $ 80 per passenger. Great ​Cruiseline's variable cost of providing the dinner is $ 40 per​ passenger, and the fixed cost of operating the vessels​ (depreciation, salaries, docking​ fees, and other​ expenses) is $ 240,000 per month. The​ company's relevant range extends to 12,000 monthly passengers.
If FunTime Cruiseline has a target operating income of $30,000 per month, how many dinner cruise tickets must the company sell? First, identify the formula, then compute the target sales in units.