Thread: math quiz program

import java.io.*;
import java.lang.*;
import java.util.Random;
import java.math.*;
 
 
 
public class first{
    public static void main(String args[])throws IOException{
        BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
 
        System.out.println("Mathematical Operations Drill");
        System.out.println("1.Practice");
        System.out.println("2.Challenge");
        System.out.println();
        System.out.println("Enter choice:");
        int choice=Integer.parseInt(br.readLine());
        System.out.println("Number of items:");
        int items=Integer.parseInt(br.readLine());
 
        generator.rangen(items);
    }
 
 
public static class generator extends first{
public static void rangen(int items){
    Random rand = new Random();
	for(int counter=1; counter<items;counter++)
        {
	int x=1+rand.nextInt(100);
	int y=1+rand.nextInt(100);
        int z=1+rand.nextInt(4);
        switch(z){
            case 1:System.out.println(+x+"+"+y+"=");break;
            case 2:System.out.println(+x+"-"+y+"=");break;
            case 3:System.out.println(+x+"*"+y+"=");break;
            case 4:System.out.println(+x+"/"+y+"=");break;
            }
        }
        }
}
}

How can I store the user's answers into an array? pls help.