Answer: No. She turns away business when the cost of an additional unit exceeds the income from it.
Step-by-step explanation:
In order to maximize production, the optimal point at which Hester should wash cars is the point where marginal revenue equals marginal cost. Marginal cost should not be above marginal revenue because it would mean that a marginal loss is being made.
At the 101st car, Hester would make a marginal loss of $0.05 because the cost of $10.05 to wash exceeds the revenue of $10.00 that she charges the customer. She should therefore not accept this or additional business because it will lead to her incurring losses.