Adding even numbers from 1-20 applying METHODS

This is our class work, the problem is to add even numbers from 1-20 using methods.

WITH RETURN TYPE WITH PARAMETER

package gene1;
import java.util.Scanner;
public class Gene1 {
static Scanner console=new Scanner(System.in);
    public static void main(String[] args) {
     
        int sum=0;
        System.out.println( "sum = " +Odd(sum) );
       }
 
    static int Odd(int x){
         for(int i=0;i<=20;i+=2){
           x=x+i;
     
    }
         return x;
}
 
}

WITH PARAMETER WITHOUT RETURN TYPE

package gene2;
import java.util.Scanner;
public class Gene2 {
static Scanner console=new Scanner (System.in);
    public static void main(String[] args) {
     
        int sum=0;
        Even(sum);
        }
 
    static void Even(int x){
         for(int i=0;i<=20;i+=2){
           x=x+i;
       

    }
         System.out.println("sum="+x);
    }
   
}

WITH RETURN TYPE WITHOUT PARAMETER

package gene3;
import java.util.Scanner;
public class Gene3 {
    static Scanner console=new Scanner(System.in);
    public static void main(String[] args) {
        
        Even();
        
    }
    private static int Even(){
        int x = 0;
        for(int i=0;i<=20;i+=2){
           x=x+i;
             System.out.println("sum = "+x);
         
    }
        return x;
}

}