Answer:
a. We need more information to answer
Step-by-step explanation:
In order to correctly answer his question we need more information. Economy is all about the margin, i.e. marginal revenue versus marginal cost. We are given the marginal revenue ($20/hr of tutoring services) but we are not given the marginal costs of tutoring. We only know that the cost of tutoring the first hour is $14, but what about the rest of the hours. Since you have 5 clients, you must be tutoring more than 1 hour per day. It is always easier to determine the marginal revenue since we determine it, while we cannot determine which costs we would like to incur.
Profits should be maximized when marginal revenue = marginal cost, but unless we know the marginal cost of tutoring the rest of the students we simply cannot answer this question.