A simple project Following Classes: 1. Student Class 2. Subject Class 3. ExamPaper Class Aggregation example: when you have field in one class that are also the object in another class, there comes a concept what is called aggregation. We can access those object members from this class object using aggregation concept. See code in main method for aggregation: System.out.println(paper.getSubject().getSubjectCode()); //similarily if you want to extract only the student number, see how you can System.out.println("Student number:"+paper.getStudent().getStudentNumber()); Let us see the complete project involving all the above classes in intellij package com.example; public class classAndObjects { public static void main(String[] args) { Subject subject1 = new Subject ("ETEE 310", "MP&MC"); Student std1=new Student("Ravinder", 1234); Exampaper paper = new Exampaper(std1, subject1, 100); //System.out.println(paper); //we can extract more information from paper object, say we want to know the subject code. //See the