Develop the ERD and write the relation notation for the following scenarios. For each scenario state how many relations would be need to implement the relationship. Account for the cardinality and participation in each relationship on your ERD.

a. A company would like to track the Employee Id, Name, Dob, age (derived from DOB) and emails, mobile numbers and home telephone of its employees. A supervisor who is an employee may supervise other Employees. All employees must be supervised by a supervisor. Supervisors are allowed to supervisor themselves along with the employees they already supervise. One employee can have only one supervisor.

b. Change the scenario in part a to employees can change supervisors over a period of time.