diff --git a/src/main/java/Cohort.java b/src/main/java/Cohort.java
new file mode 100644
index 00000000..4baa092f
--- /dev/null
+++ b/src/main/java/Cohort.java
@@ -0,0 +1,27 @@
+import java.util.ArrayList;
+import java.util.List;
+
+public class Cohort {
+
+    private List<Student> students;
+
+    public Cohort() {
+        this.students = new ArrayList<>();
+    }
+
+    public double getCohortAverage() {
+        double avg = 0;
+        for (Student student: this.getStudents()) {
+            avg += student.getGradeAverage();
+        }
+        return avg / this.getStudents().size();
+    }
+
+    public void addStudent(Student student){
+        students.add(student);
+    }
+
+    public List<Student> getStudents() {
+        return students;
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/Student.java b/src/main/java/Student.java
new file mode 100644
index 00000000..686e1ca6
--- /dev/null
+++ b/src/main/java/Student.java
@@ -0,0 +1,38 @@
+import java.util.ArrayList;
+
+public class Student {
+
+    private long id;
+    private String name;
+    private ArrayList<Integer> grades;
+
+    public Student(long id, String name){
+        this.id = id;
+        this.name = name;
+        this.grades = new ArrayList<>();
+    }
+
+    public long getId() {
+        return this.id;
+    }
+
+    public String getName(){
+        return this.name;
+    }
+
+    public void addGrade(int grade) {
+        grades.add(grade);
+    }
+
+    public ArrayList<Integer> getGrades() {
+        return this.grades;
+    }
+
+    public double getGradeAverage() {
+        double sum = 0;
+        for (int grade : this.grades) {
+            sum += grade;
+        }
+        return sum / getGrades().size();
+    }
+}
\ No newline at end of file
diff --git a/src/test/java/CohortTest.java b/src/test/java/CohortTest.java
new file mode 100644
index 00000000..9de5c0ed
--- /dev/null
+++ b/src/test/java/CohortTest.java
@@ -0,0 +1,2 @@
+public class CohortTest {
+}
diff --git a/src/test/java/StudentTest.java b/src/test/java/StudentTest.java
new file mode 100644
index 00000000..9d4bb6b3
--- /dev/null
+++ b/src/test/java/StudentTest.java
@@ -0,0 +1,88 @@
+import org.junit.Test;
+import static org.junit.Assert.*;
+
+public class StudentTest {
+
+    @Test
+    public void testIfStudentCanBeCreated(){
+        Student fer = new Student(1L, "fer");
+        Student nullStudent = null;
+        assertNotNull(fer);
+        assertNull(nullStudent);
+    }
+
+    @Test
+    public void testIfFieldsAreSet(){
+        Student fer = new Student(1L, "fer");
+        assertEquals(1L, fer.getId());
+        assertEquals("fer", fer.getName());
+
+        Student rosie = new Student(40L, "Rosie");
+        assertEquals(40L, rosie.getId());
+        assertEquals("Rosie", rosie.getName());
+    }
+
+    @Test
+    public void testIfAddGradeWorks(){
+        Student fer = new Student(1L, "fer");
+        assertEquals(0, fer.getGrades().size());
+        fer.addGrade(90);
+        assertEquals(1, fer.getGrades().size());
+        fer.addGrade(70);
+        assertEquals(2, fer.getGrades().size());
+    }
+
+    @Test
+    public void testIfGetGradesWorks(){
+        Student fer = new Student(1L, "fer");
+        fer.addGrade(90);
+        fer.addGrade(70);
+        assertSame(90, fer.getGrades().get(0));
+        assertSame(70, fer.getGrades().get(1));
+    }
+
+    @Test
+    public void testIfGetAVGWorks(){
+        Student fer = new Student(1L, "fer");
+        fer.addGrade(90);
+        fer.addGrade(70); // 160 / 2 = 80
+        assertEquals(80, fer.getGradeAverage(), 0);
+        fer.addGrade(50); // 210 / 3 = 70
+        assertEquals(70, fer.getGradeAverage(), 0);
+    }
+
+        @Test
+        public void testCreateStudent(){
+            Student fer = new Student(1L, "fer");
+            Student ryan = null;
+            assertNull(ryan);
+            assertNotNull(fer);
+        }
+
+        @Test
+        public void testStudentFields(){
+            Student fer = new Student(1L, "fer");
+            assertSame(1L, fer.getId());
+            assertSame("fer", fer.getName());
+            assertSame(0, fer.getGrades().size());
+        }
+
+
+        @Test
+        public void testAddGrade(){
+            Student fer = new Student(1L, "fer");
+            fer.addGrade(100);
+            assertSame(100, fer.getGrades().get(0));
+            fer.addGrade(80);
+            assertSame(80, fer.getGrades().get(1));
+        }
+
+        @Test
+        public void testAverageGrade(){
+            Student fer = new Student(1L, "fer");
+            fer.addGrade(100);
+            fer.addGrade(80);
+            assertEquals(90, fer.getGradeAverage(), 0);
+        }
+
+}
\ No newline at end of file