diff --git a/exercise1/Human.java b/exercise1/Human.java
index 4b9b45e..1ac5542 100644
--- a/exercise1/Human.java
+++ b/exercise1/Human.java
@@ -1,6 +1,5 @@
 package exercise1;
 
-// 1.Change the staticPrint() method so that its output cannot be changed in all the classes that extend or implement Human.
 
 public abstract class Human {
     private String fullName;
@@ -17,7 +16,7 @@ public void sayMyName() {
         System.out.println("im a human!");
     }
 
-    public void staticPrint() {
+    public final void staticPrint() {
         System.out.println("this function should always print this string in all subclasses");
     }
 }
diff --git a/exercise1/Main.java b/exercise1/Main.java
index ad47473..5fce533 100644
--- a/exercise1/Main.java
+++ b/exercise1/Main.java
@@ -3,16 +3,20 @@
 import java.util.ArrayList;
 import java.util.List;
 
-// After completing the Student and Professor classes, create an instance of each one:
-//  6. Using instanceof keyword, check if the instances that you have created are really an instance of human class
-//  7. Write the following code: Human human = new Student(); What is the output of human.sayMyName() ?
-//  8. Now write this:
-//  Human human = new Professor();
-//  What is the output of human.sayMyName() ?
-//  9. What can we understand from question 7 and 8?
- 
 public class Main {
+
     public static void main(String[] args) {
+        Student student1 = new Student("Ali Arad", 123456, "Mathematics", "Tehran");
+        Professor professor1 = new Professor("sara mohamadi", "Mathematics", "Science", 10);
+
+        System.out.println(student1 instanceof Human);
+        System.out.println(professor1 instanceof Human);
+
+        Human human = new Student("zahra karimi", 54321, "Chemistry", "london");
+        human.sayMyName();
+
+        human = new Professor("maryam", "Physics", "Engineering", 5);
+        human.sayMyName();
 
     }
 }
diff --git a/exercise1/Professor.java b/exercise1/Professor.java
index 7c3b522..3640a0f 100644
--- a/exercise1/Professor.java
+++ b/exercise1/Professor.java
@@ -1,8 +1,62 @@
 package exercise1;
 
-// Implement or extend the human class to make a professor class...
-//  4.Add the following attributes to this class with setters and getters: professorSpecialty, professorFaculty, numberOfCourse
-//  5.Change the professor class so that when we call the sayMyName() method on an instance of this class, fullName of the professor plus their professorFaculty is printed.
- 
-public class Professor {
+public class Professor extends Human {
+    private String professorSpecialty;
+    private String professorFaculty;
+    private int numberOfCourses;
+
+    public Professor(String fullName, String professorSpecialty, String professorFaculty, int numberOfCourses) {
+        setFullName(fullName);
+        this.professorSpecialty = professorSpecialty;
+        this.professorFaculty = professorFaculty;
+        this.numberOfCourses = numberOfCourses;
+    }
+
+    public void sayMyName() {
+        System.out.println(getFullName() + " , " + professorFaculty);
+    }
+
+    public String getProfessorSpecialty() {
+        return professorSpecialty;
+    }
+
+    public void setProfessorSpecialty(String professorSpecialty) {
+        this.professorSpecialty = professorSpecialty;
+    }
+
+    public String getProfessorFaculty() {
+        return professorFaculty;
+    }
+
+    public void setProfessorFaculty(String professorFaculty) {
+        this.professorFaculty = professorFaculty;
+    }
+
+    public int getNumberOfCourses() {
+        return numberOfCourses;
+    }
+
+    public void setNumberOfCourses(int numberOfCourses) {
+        this.numberOfCourses = numberOfCourses;
+    }
+
+    public static void main(String[] args) {
+        Professor p = new Professor("", "", "", 0);
+
+        p.staticPrint();
+
+        p.setFullName("sara mohamadi");
+        System.out.println(p.getFullName());
+
+        p.setProfessorSpecialty("Mathematics");
+        System.out.println(p.getProfessorSpecialty());
+
+        p.setProfessorFaculty("Science");
+        System.out.println(p.getProfessorFaculty());
+
+        p.setNumberOfCourses(10);
+        System.out.println(p.getNumberOfCourses());
+
+        p.sayMyName();
+    }
 }
diff --git a/exercise1/Student.java b/exercise1/Student.java
index 0f8f606..ab7a828 100644
--- a/exercise1/Student.java
+++ b/exercise1/Student.java
@@ -1,9 +1,62 @@
 package exercise1;
 
-// Human is an abstract concept, so we have created an abstract class to represent it...
-// Implement or extend the Human class to make a student class.
-// 2. Change the student class so that when we call the sayMyName() method on an instance of this class, the fullName attribute of the student is printed.
-// 3.Add the following attributes to the student class with setters and getters: studentNumber, majorName, universityName
+public class Student extends Human {
+    private int studentNumber;
+    private String majorName;
+    private String universityName;
 
-public class Student {
+    public Student(String fullName, int studentNumber, String majorName, String universityName) {
+        setFullName(fullName);
+        this.studentNumber = studentNumber;
+        this.majorName = majorName;
+        this.universityName = universityName;
+    }
+
+    public void sayMyName() {
+        System.out.println(getFullName());
+    }
+
+    public int getStudentNumber() {
+        return studentNumber;
+    }
+
+    public void setStudentNumber(int studentNumber) {
+        this.studentNumber = studentNumber;
+    }
+
+    public String getMajorName() {
+        return majorName;
+    }
+
+    public void setMajorName(String majorName) {
+        this.majorName = majorName;
+    }
+
+    public String getUniversityName() {
+        return universityName;
+    }
+
+    public void setUniversityName(String universityName) {
+        this.universityName = universityName;
+    }
+
+    public static void main(String[] args) {
+        Student s = new Student("", 0, "", "");
+        s.sayMyName();
+
+
+        s.staticPrint();
+
+        s.setFullName("Ali Arad");
+        System.out.println(s.getFullName());
+
+        s.setStudentNumber(123456);
+        System.out.println(s.getStudentNumber());
+
+        s.setMajorName("Mathematics");
+        System.out.println(s.getMajorName());
+
+        s.setUniversityName("Tehran");
+        System.out.println(s.getUniversityName());
+    }
 }
diff --git a/exercise1/q_9.pdf b/exercise1/q_9.pdf
new file mode 100644
index 0000000..dc7fad2
Binary files /dev/null and b/exercise1/q_9.pdf differ