public void Task2()
    {
        var query1 = from employees in employeeList
                     join salary in salaryList.Where(s => s.Type == SalaryType.Monthly)
                     on employees.EmployeeID equals salary.EmployeeID into EmpGrp
                     select new
        {
            EmployeeId  = employees.EmployeeID,
            FirstName   = employees.EmployeeFirstName,
            LastName    = employees.EmployeeLastName,
            EmployeeAge = employees.Age,
            Sum         = EmpGrp.Sum(s => s.Amount)
        };

        Console.WriteLine("Employee details of 2nd oldest employee including his/her total monthly salary : ");
        Console.WriteLine();
        foreach (var emps in query1.OrderByDescending(a => a.EmployeeAge).Skip(1).Take(1))
        {
            Console.WriteLine($"Employee Id : {emps.EmployeeId} " +
                              $"Employee Name : " +
                              $"{emps.FirstName} " +
                              $"{emps.LastName} " +
                              $"Employee Age : {emps.EmployeeAge} " +
                              $"Employee Total Monthly Salary : {emps.Sum}");
        }
        Console.WriteLine();
    }
    public void Task3()
    {
        var query1 = from employees in employeeList.Where(e => e.Age > 30)
                     join salary in salaryList
                     on employees.EmployeeID equals salary.EmployeeID into EmpGrp
                     select new
        {
            Id          = employees.EmployeeID,
            Name        = employees.EmployeeFirstName,
            EmployeeAge = employees.Age,
            Avg         = EmpGrp.Average(s => s.Amount)
        } into results
        select results;

        Console.WriteLine("Mean of Monthly, Performance, Bonus salary of employees with age greater than 30 : ");
        Console.WriteLine();
        foreach (var emps in query1)
        {
            Console.WriteLine($"Employee Id : {emps.Id}  Employee Name : {emps.Name}  Employee Age : {emps.EmployeeAge}  Employee Salary Average : {emps.Avg}");
        }
    }
    public void Task1()
    {
        var query1 = from employees in employeeList
                     join salary in salaryList
                     on employees.EmployeeID equals salary.EmployeeID into EmpGrp
                     select new
        {
            FirstName = employees.EmployeeFirstName,
            LastName  = employees.EmployeeLastName,
            Sum       = EmpGrp.Sum(s => s.Amount)
        };


        Console.WriteLine("Total salary Of All The Employee in ascending order of their salary : ");
        Console.WriteLine();
        foreach (var emps in query1.OrderBy(s => s.Sum))
        {
            Console.WriteLine($"Employee Name : " +
                              $"{emps.FirstName} " +
                              $"{emps.LastName} " +
                              $"  Employee Salary : {emps.Sum}");
        }
        Console.WriteLine();
    }