Labour Number of meals served per day 0 10 28 OF A WN- 45 56 65 Luigi owns an Italian restaurant. His costs include his employees (e.g., cooks, waiters, and waitresses), food, and fixed overhead expenses (e.g., rent). The food cost per meal is constant. The production function relating number of meals served per day and number of employees hired per day is given above. The marginal cost of serving a meal is lowest at | units of output. (Round your response to the nearest whole number.) The average variable cost of serving a meal is lowest at |units of output. (Round your response to the nearest whole number.)