5. The return on investment for a service is given by ROI = 100 percent, wherer is the money earned by providing the service, and c is the cost to provide the service. A positive ROI indicates a gain, while a negative ROI indicates loss. Sandie provides management consultation, for which she earns $210 per hour and has a fixed cost of $2400 for leasing office space and paying an assistant. (a) Write Sandie's ROI as a linear function of h, the number of hours she has consulted. (Your final answer should no longer have any r or c variables in it, only h.) (b) Write a sentence interpreting the slope of the ROI function in the applied context, including units. (c) At what point does Sandie break even (that is, how many hours does she need to consult in order to have a zero ROI)? (d) Sandie is currently able to consult for 14 hours, and her financial adviser recommends an ROI of at least 15% (in order to balance against inflation and taxes). Is she meeting the recommendations of her adviser? Challenge Exercises: The following exercises are of a greater difficulty than the earlier ones, though still matched to our course objectives. These exercises are not intended to prepare you for test questions, instead they expose you to more complex, real-world scenarios. You may struggle more with these questions than the Routine exercises. Remember your problem solving strategies! Read carefully and repeatedly. What words are familiar in the problem statement? What terms have been defined in the class, versus what is being provided to you within the exercise itself? Who can you work with for assistance