Here you go - To the 3 queries you posted.

Select a.employeename ||' earns '||a.salary||' monthly but wants '||a.salary*3 as DreamSalaries
from employeeTable a

Select a.LastName, a.hireDate, to_char(a.hiredate,'DAY')
from employeeTable a
order by to_char(a.hiredate,'D')

Select a.departmentname as dname, a.locationname as loc, count(*) as numberofpeople, round(avg(b.salary),2)  Salary
from dept a, emp b
where a.deptno=b.deptno
group by a.departmentname