I do not understand part C

Qwik Service has over 200 auto-maintenance service outlets nationwide. It provides primarily two lines of service: oil changes and brake repair. Oil change-related services represent 75% of its sales and provide a contribution margin ratio of 20%. Brake repair represents 25% of its sales and provides a 60% contribution margin ratio. The company's fixed costs are $15,000,000 (that is, $75,000 per service outlet). a. Calculate the dollar amount of each type of service that the company must provide in order to break even b. The company has a desired net income of $45,000 per service outlet. What is the dollar amount of each type of service that must be provided by each service outlet to meet its target net income per outlet? c. If the company changes its sales mix to 60% for oil change service and 40% for break repair service, what is the break even sales for the company