1. Write a query to display the last name, department number, and salary of any employee whose
   department number and salary both match the department number and salary of any employee
   who earns a commission.

2. Display the last name, department name, and salary of any employee whose salary and
   commission match the salary and commission of any employee located in location ID1700.

3. Create a query to display the last name, hire date, and salary for all employees who have the
   same salary and commission as Kochhar.
   Note: Do not display Kochhar in the result set.

4. Create a query to display the employees who earn a salary that is higher than the salary of
   all of the sales managers (JOB_ID = ’SA_MAN’). Sort the results on salary from highest to
   lowest.

5. Display the details of the employee ID, last name, and department ID of those employees who
   live in cities whose name begins with T.

6. Write a query to find all employees who earn more than the average salary in their
   departments. Display last name, salary, department ID, and the average salary for the
   department. Sort by average salary. Use aliases for the columns retrieved by the query as
   shown in the sample output.

7. Find all employees who are not supervisors.
   a. First do this by using the NOT EXISTS operator.
   b. Can this be done by using the NOT IN operator? How, or why not?

8. Write a query to display the last names of the employees who earn less than the average salary
   in their departments.

9. Write a query to display the last names of employees who have one or more coworkers in their
   departments with later hire dates but higher salaries.

10. Write a query to display the employee ID, last names, and department names of all employees.
    Note: Use a scalar subquery to retrieve the department name in the SELECT statement.

11. Write a query to display the department names of those departments whose total salary cost is
    above one-eighth (1/8) of the total salary cost of the whole company. Use the WITH clause to
    write this query. Name the query SUMMARY.