Which department IDs have manager ids that are from 0-100?
select department_id from departments where manager_id > = 0 and manager_id < = 100
What about from 100 - 200?
select department_id from departments where manager_id > = 100 and manager_id < = 200
What are the employee ids who work in those departments?
select employee_id from employees where department_id in ( select department_id from departments where manager_id between 100 and 200 )
What about employees who don't work with employees in those departments?
select * from employees where department_id not in ( select department_id from departments where manager_id between 100 and 200 )