The utility that Miriam gets by consuming food F and clothing C is given by u(F,C)=DC.
1. Draw the indifference curve associated with a utility level of 12 and an indifference curve associated with a utility level of 24. Are the indifference curves convex?.
2. Suppose that food cost $1 per unit, and clothing cost $3 per unit, and Miriam has $12 to spend on food and clothing. Graph the budget line that she faces.
3. What is the Utility-maximizing choice of food and clothing?
4. What is the marginal rate of substitution of food for clothing when utility is maximized?
I don't see any reason to report this, but, truth be told, it's clearly a homework question that probably will make sense mainly to anyone who's done the course in question (or, perhaps, anyone with a background in formal economics). Since the only person here (probably) who's done that course is you, the sensible thing to do is to refer back to your course notes, where the terms and methods will be explained clearly.