/* package codechef; // don't place package name! */

import java.util.*;
import java.lang.*;
import java.io.*;

/* Name of the class has to be "Main" only if the class is public. */
public class Codechef
{
	public static void main (String[] args) throws java.lang.Exception
	{
		// your code goes here
		
	Scanner sc= new Scanner(System.in);
	int t= sc.nextInt();
	while(t-->0){
	    int n= sc.nextInt();
	    int[] arr= new int[n];
	    int sum=0;
	    for(int i=0;i<n;i++){
	        arr[i]= sc.nextInt();
	        sum+=arr[i];
	    }
	    int extra= sum%n;
	    System.out.println(extra*(n-extra));
	}
	}
}
