need help with a to c

Tracey and her family are planning for a "Hop-on Hop-off" tour business with double decker busses in Victoria, BC for 90 days this summer. She bought 3 double decker busses with her retirement funds at a good bargain for $7000 each. The double decker busses are powered by the new electric savvy technology that can be driven an average of 80 kilometers in a day. Tracey bought two additional batteries for $1100 each, believing that she will be able to keep her double decker busses adequately charged to meet her expected daily demand. Additionally, Tracey incurs other expenses such as space rental for the busses when they are idle and utilities for a total of $100 per day, and an insurance of $15 daily per double decker bus. (a) If Tracey charges $35 per half-hour tour per group of tourists, that is approximately 10 kilometers, how much profit does she expect to make this summer? (b) What is the lowest price she can charge per half-hour tour and still breakeven? (c) If she wants to realize a profit of $500 per day, how much more should she charge per halfhour tour