Help Printing an ArrayList

[RSH]

Hey guys,

I'm working on a Practice Test program where I store 200 objects (a mixture of multiplication, subtraction, and addition questions) and then print them out twice - once without the answers and once with the answers.

I created an abstract Questions class from which subclasses Multiplication, Addition, and Subtraction, all inherit. In Questions class I have the following two print methods:

public void printQuestion() {
	System.out.println(num1 + " " + operator + " " + num2 + " = ");
}
public void printQuestionWithAnswer() {
	System.out.println(num1 + " " + operator + " " + num2 + " = " + solution);
}

The variables are all defined by a computeAnswer() method within the subclasses. In my main I created an ArrayList:

ArrayList <Questions> QuestionsArrayList = new ArrayList <Questions>();

I then add a random selection of unique questions:

Random rand2 = new Random();
	
		for(int j = 0; j<199; j++){
			int k = rand2.nextInt(3)+1;
			if (k == 1){
				boolean i;
				while(i = false){
				Addition a = new Addition();
				if (!QuestionsArrayList.contains(a)){
					QuestionsArrayList.add(a);
					i = true;
				}
				else
					i = false;
				}
				}
			if (k == 2){
				boolean i;
				while(i = false){
				Subtraction s = new Subtraction();
				if (!QuestionsArrayList.contains(s)){
					QuestionsArrayList.add(s);
					i = true;
				}
				else
					i = false;
				}
			}
			if (k == 3){
				boolean i;
				while(i = false){
				Multiplication m = new Multiplication();
				if (!QuestionsArrayList.contains(m)){
					QuestionsArrayList.add(m);
					i = true;
				}
				else
					i = false;
				}

Now, I would like to print them out once without answers and once with the answers. I imagine I will use something like the following, but I haven't been able to figure it out completely:

for(int i=0; i<100; i++){
    QuestionsArrayList.get(i).printQuestion();
}

Can anybody help?