6. Using relational algebra, produce a report of all employees from the IT and planning departments who are born after 1990. The following tables form part of a database held in an RDBMS: Employee (empNo, fName, IName, address, DOB, sex, position, deptNo) Department (deptNo, deptName, mgrEmpNo) Project (projNo, projName, deptNo) WorksOn (empNo, projNo, dateWorked, hoursWorked) where Employee Department Project and WorksOn contains employee details and empNo is the key. contains department details and deptNo is the key. mgrEmpNo identifies the employee who is the manager of the department. There is only one manager for each department. contains details of the projects in each department and the key is projNo (no two departments can run the same project). contains details of the hours worked by employees on each project, and empNo/ projNo/dateWorked form the key. Formulate the following queries in relational algebra, tuple relational calculus, and domain relational calculus. a) List all employees. b) List all the details of employees who are female and born after 1990. c) List all employees who are not managers and are paid more than $1500. d) Produce a list of the names and addresses of all employees who work for the IT department. e) Produce a list of the names of all employees who work on the SCCS project. f) Produce a complete list of all managers who are due to retire this year, in alphabetical order of surname. g) Formulate the following queries in relational algebra. h) Find out how many managers are female. i) Produce a report of all projects under the IT department. j) Using the union operator, retrieve the list of employees who are neither managers nor supervisors. Attributes to be retrieved are first name, last name, position, sex and department number.