Using relational algebra, list the total number of employees in each department for those departments with more than 10 employees. Create an appropriate heading for the columns of the results table.

The following tables form part of a Library database held in an RDBMS.

Employee (empNo, fName, lName, address, DOB, sex, position, deptNo)

Department (deptNo, deptName, mgrEmpNo)

Project (projNo, projName, deptNo)

WorksOn (empNo, projNo, dateWorked, hoursWorked)

Where

Employee contains employee details and empNo is the key.

Department contains department details and deptNo is the key, mgr No identifies the employee who is the manager of the department. There is only one manager for each department.

Project contains detailso f projects in each department and projNo is the key. No two departments can run the same project.

WorkOn contains details of the hours worked by employees on each project and empNo/projeNo/dateWorked form the key.