John takes microeconomics with Professor Nice. Professor Nice gives 2 exams, a mid-term and a final, and he marks each exam out of 100. Initially, the mid-term exam counts for 40% of the overall grade while the final exam counts for 60%. However, being nice, the professor introduces another option of weighing the midterm 20% and the final 80%, and each student's overall grade is calculated using the weighing option that gives him or her a higher overall grade. John strictly prefers a higher grade to a lower one.

(a) Draw the indifference curve (for midterm and final exam marks) such that John's overall grade is 80.

(b) Are John's preferences convex and (strongly) monotonic? Explain your answer.