I cant figure out c and d. pls help thank you

Flow Cruiseline offers nightly dinner cruises departing from several cities on the East Coast of the United States including Charleston, Baltimore, and Alexandria. Dinner cruise tickets sell for $80 per passenger. Flow 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 $360,000 per month. The company's relevant range extends to 20,000 monthly passengers. Use this information to compute the following: a. What is the contribution margin per passenger? b. What is the contribution margin ratio? c. Use the unit contribution margin to project operating income if monthly sales total 17,000 passengers. d. Use the contribution margin ratio to project operating income if monthly sales revenue totals $775,000. a. What is the contribution margin per passenger? First identify the formula, then compute the contribution margin per passenger. b. What is the contribution margin ratio? (Enter the contribution margin ratio as a whole percent.) First identify the formula, then compute the contribution margin ratio. c. Use the unit contribution margin to project operating income if monthly sales total 17,000 passengers. The operating income is