Question 9 Ivan earns 80 per week and needs to decide how many cans of Coke and sandwiches to buy. Each sandwich costs 4 and every can of Coke costs 2. His utility function is U(s.c) = so. where 5 stands for sandwich and c for can of Coke. (a) Find an equation for Ivan's budget constraint and show the budget constraint in a diagram. [6 marks] (b) Calculate the optimal weekly amounts of sandwiches and cans of Coke for Ivan and show the optimal bundle on a graph. [6 marks] (c) Ivan has worked hard this year and his boss decides to give him a raise. He now earns 100 per week. Show the increase in income on a graph and discuss how it affects his demand for sandwiches and Coke. [6 marks] to (d) Explain what would happen if the price of sandwiches went up 9755 and income remained at 100 per week. Show lvan's new budget line on a graph. Would Ivan still demand the same amounts of sandwiches and cans of Coke? [6 marks] (e) Explain the difference between normal, inferior, and Giffen goods and what sign the income and substitution effects are in each of these cases. Are sandwiches a normal good in this case? [6 marks]