java问题，请高手解决

Question

今天去一家公司机试；
遇到一个这样的问题：
设计一份考试程序，包含四道单选题和四道多选题，单选题答对一道得1分，多选答对一道得1.5分，
要求学生能在程序的指导下做题，一直得到最终的分数。
要求用JAVA实现。运用面向对象的方式，至少包含试卷，问题，答案三个类。
这道题把我困住了，请各位高手指点迷津，小弟先谢过。

Answer 1

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*;
import java.awt.font.*;
import java.util.*;
import java.io.*;
public class Exam {
    public static void main(String[] args) {
        JFrame f = new ExamFrame();
        f.setVisible(true);
    }
}class ExamFrame extends JFrame {
    static int singlequestion;
    static int singleanswer;
    static int multiplyquestion;
    static int multiplyanswer;
    static {
        Properties prop = new Properties();
        try {
            prop.load(new FileInputStream("exam.properties"));
        } catch (FileNotFoundException ex) {
            ex.printStackTrace();
        } catch (IOException ex) {
            ex.printStackTrace();
        }
        singlequestion = Integer.parseInt(prop.getProperty("singlequestion"));
        singleanswer = Integer.parseInt(prop.getProperty("singleanswer"));
        multiplyanswer = Integer.parseInt(prop.getProperty("multiplyanswer"));
        multiplyquestion = Integer.parseInt(prop.getProperty("multiplyquestion"));
    }
    Question[] qs = new Question[singlequestion];
    Question2[] q2s = new Question2[multiplyquestion];
    Score score = new Score();
    int rightcount;
    JLabel scoreLabel = new JLabel();
    public ExamFrame() {
        setSize(600,700);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setLayout(new GridLayout(12,1));
        JPanel titlePanel = new TitlePanel();
        add(titlePanel);
        Scanner scan = null;
        try {
            scan = new Scanner(new File("exam.txt"));
        } catch (FileNotFoundException ex) {
            ex.printStackTrace();
        }
        int index=0;
        while(scan.hasNextLine()&&index<singlequestion) {
            String temp = scan.nextLine();  //System.out.println(temp);
            String[] temps = temp.split("!");
            Answer[] answers = new Answer[singleanswer];
            ButtonGroup group = new ButtonGroup();
            for(int i = 1;i<5;i++) {
                answers[i-1] = new Answer(temps[i]);
                group.add(answers[i-1]);
            }
           qs[index] = new Question(temps[0],score,answers);
           qs[index].setRightAnswer(Integer.parseInt(temps[5]));
            add(qs[index++]);
            
        }
        index = 0;
        while(scan.hasNextLine()) {
            String temp = scan.nextLine();
            String[] temps = temp.split("!");
            Answer2[] answer2s = new Answer2[multiplyanswer];
            for(int i=1;i<7;i++) {
                answer2s[i-1] = new Answer2(temps[i]);
            }
            q2s[index] = new Question2(temps[0],score,answer2s);
            int answersize = temps.length - 7;
            int[] rightanswers = new int[answersize];
            int index2 = 0;
            for(int i = 7;i<temps.length;i++) {
                rightanswers[index2++] = Integer.parseInt(temps[i]);
            }
            q2s[index].setRightAnswers(rightanswers);
            add(q2s[index++]);
        }
        JPanel buttonPanel = new JPanel();
        JButton submit = new JButton("Submit");
        add(buttonPanel);
        buttonPanel.add(submit);
        submit.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                EventQueue.invokeLater(new Runnable() {
                    public void run() {
                   for(Question temp:qs) {
                        if(temp.check()) {
                        rightcount+=1;
                        temp.score();                   
                       }
                   }
                   for(Question2 temp2:q2s) {
                       if(temp2.check()) {
                        rightcount+=1;
                        temp2.score();                   
                       }
                   }
                    scoreLabel.setText("you gave "+rightcount+" right answer,\r\n you got "+score.getResult()+" point");
                    add(scoreLabel);
                    rightcount = 0;
                    validate();
            } 
                });
            }  
        });
    }
}class Answer extends JRadioButton{
    public Answer(String text) {
        setText(text);
    }}
class Answer2 extends JCheckBox {
   //String text;
    public Answer2(String text) {
        setText(text);
    }
}
class Question extends JPanel {
    String text;
    Score score;
    Answer[] answers;
    int flag ;
    boolean inited;
    public Question(String text,Score s,Answer[] as) {
        this.text = text;
        score = s;
        answers = as;
        setLayout(new GridLayout(2,1));
        JLabel l = new JLabel(text);
        add(l);
        JPanel p = new JPanel();
        add(p);
        p.setLayout(new GridLayout(1,4));
        for(int i = 0;i<answers.length;i++) 
            p.add(answers[i]);
    }
    public void setRightAnswer(int i) {
        inited = true;
        flag = i;
    }    public boolean check() {
        if(inited&&answers[flag].isSelected())
            return true;
        return false;
    }
    public void score() {
            score.add(1);
    }
}

Answer 2

class Question2 extends JPanel {
    //String text;
    Answer2[] answers;
    Score score;
    int[] rightanswers;
    int flag;
    public Question2(String text,Score s,Answer2[] sa) {
       // this.text = text;
        score = s;
        answers = sa;
        setLayout(new GridLayout(2,1));
        JLabel l = new JLabel(text);
        add(l);
        int size = answers.length;
        JPanel buttonPanel = new JPanel();
        add(buttonPanel);
        buttonPanel.setLayout(new GridLayout(1,size));
        for(int i=0;i<size;i++)
            buttonPanel.add(answers[i]);
    }
    public void setRightAnswers(int[] f) {
        rightanswers = f;
        flag = f.length;
    }
    public void score() {
        if(check())
            score.add(1.5);
    }
    public boolean check(){
        for(int index:rightanswers) {
            if(!answers[index].isSelected()) 
                return false;
        }
        for(int i=0;i<answers.length;i++) 
            if(answers[i].isSelected()&&!insideAset(i,rightanswers)) 
                return false;
        return true;
    }
        public static boolean insideAset(int i,int[] arr) {
            for(int temp:arr) {
                if(temp==i)
                    return true;
            }
            return false;
        }
}class Score {
    double score ;
    public void add(double d) {
        score += d;
    }
    public double get() {
        return score;
    }
    public double getResult() {
        double result = score;
        score = 0;
        return result;
    }
}
class TitlePanel extends JPanel {
    static String text ; // = "Exam Test:for the java programmer";
    static {
       Properties prop = new Properties();
        try {
            prop.load(new FileInputStream("exam.properties"));
        } catch (FileNotFoundException ex) {
            ex.printStackTrace();
        } catch (IOException ex) {
            ex.printStackTrace();
        }
       text = prop.getProperty("title");
    }
    public TitlePanel() {}
    public TitlePanel(String text) {
        text = text;
    }
    public void paintComponent(Graphics g) {
        super.paintComponent(g);
        if(text==null) {
            System.out.println("paint:text == null!");
            return;
        }
        Graphics2D g2 = (Graphics2D)g;
        Font titleFont = new Font("SansSerif", Font.BOLD, 20);
        FontRenderContext context = g2.getFontRenderContext();
        Rectangle2D rect = titleFont.getStringBounds(text,context);
        float X = (float)(getWidth()-rect.getWidth())/2;
        float Y = -(float)(rect.getY());
        System.out.println(X+" "+Y);
        g2.setFont(titleFont);
        g2.drawString(text,X,Y);
    }
}
这是我当时的解决方案，用下面几个类来实现：Exam,ExamFrame,Score,Question,Answer,Question2,Answer2,这几个主要的类再加上一个试卷标题类TitlePanel。
Question和Question2分别表示单选题和多选题，Answer和Answer2分别表示单选答案和多选答案。由于单选答案我想用单选框按钮实现，而多选答案我想用复选框来实现，
所以我没有让他们继承同一个类，这样代码显得有点冗余。我想把Question和Question2整合进一个基类中，把Answer和Answer也整合进一个基类中，请问各位该怎样重新设计类。
请各位高手多多指教啊，先谢谢