Carina buys two goods, food, F, and clothing, C, with the utility function, U = FC + F. She has an income of 20. The price of clothing is 4. a) Derive the equation representing Carina's demand for food. b) Calculate the income and substitution effects on Carina's consumption of food when the price of food rises from 1 to 4.

An outpatient operating room charges each patient a fixed amount per surgery plus an amount per minute for use. One patient was charged 250 for a 30-minute surgery and another patient was charged 450 for a 90-minute surgery. Determine the linear function that would be used to compute the charges. Use the function to determine the charge when a patient has a 45-minute surgery.