// Task 3
public static Students[] FirstNameBeforeLast(Students[] listOfStudents)
{
return listOfStudents.Where(x => x.FirstName.CompareTo(x.LastName) < 0).ToArray();
}
// Task 4
public static Students[] FindStudentFrom18To24(Students[] listOfStudents)
{
return listOfStudents.Where(x => x.Age >= 18 && x.Age <= 24).ToArray();
}