3. Ann is taking microeconomic theory with Professor Choice. Professor Choice gives 3 exams and he marks each exam out of 100 points. He uses the following grading scheme to motivate his students to do well throughout the course. For each student, he chooses the two exams with the lowest average and this average becomes the student's final grade. The higher Ann's final grade in microeconomic theory is, the happier she is.(a) Suppose Ann got 80 on her first exam. Let r, be her score on the second exam and z, be her score on the third exam. Draw her indifference curve for scores on the second and the third exams such that her final grade is 75. (b) Are Ann's preferences monotonic? Are they strongly monotonic? Are they convex? Explain your answer in each case