Tania owns a burger shop. She sells every burger for $18. The variable cost of each burger is $8. Fixed costs are $45,000 per month. a. What is Tanias burgers contribution margin per unit? b. What is Tanias burgers contribution margin ratio? c. How many burgers does Tania need to sell in a month to obtain $4,800 operating income? d. At how many burgers per month does Tania meet the breakeven point? e. If the variable cost increases by 10%, how much should Tania increase the selling price to maintain the breakeven units?