Essay question, Thank you

Answer the following questions 1- Use diminishing marginal utility to explain why millionaires often do not have many homes, even if they can afford it. (5 Marks) 2- Can marginal utility be negative? Briefly explain with an example. (5 Marks) 3- Using graphs, show the relationship between production and costs, by using marginal Product of labor (MPL), Average Product of labor (APL), Marginal cost (MC), and Average Cost (AC) curves? (10 marks) 4- State the three cases of Returns to scale. Explain when each case could be realized