Overview: Registration department in each branch of Arab Open University is responsible for offering sections for all courses to students. In this TMA, it is required to help the head of registration department implement application to keep track of registration data for the current semester. Requirements: After a quick meeting with the head of registration department, you got the following information: It is required to store the whole data (all offered sections in the current semester) in one collection Each section has a number, course code (e.g. M251) and an instructor to teach it. In addition, it contains many students with flexibility of adding and removing students within a given limit for the maximum number of students who could register in the same section (where this limit is fixed and unified for all sections). Furthermore, there are other attributes (add at least 2 attributes from your choice). Of course, section number is unique for each course. Each instructor has a unique ID, a name and other attributes (add at least 3 attributes from your choice). Each student has a unique ID, a name and other attributes (add at least 4 attributes from your choice). Moreover, you have been informed that the following operations happen frequently: Offering a new section Adding a student to a specified section Removing a student from a specified section Retrieving the average number of students per section of a specified course Displaying all sections offered in the current semester in a format similar to the following: courseCode1: secNo1 secNo2 secNo3 courseCode2: secNo1 secNo2 secNo3 where courses and sections are sorted in ascending order Saving all the registration data into a text file Analysis:

Q1: There are common attributes and methods between students and instructors. What is the best choice for designing and writing the codes of these two classes? Explain your answer.

Q2: Draw a simple class diagram showing only relationships between the classes.