/* 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{
	    Scanner scn = new Scanner(System.in);
	    int t = scn.nextInt();
	    while(t-->0){
	        int n =scn.nextInt();
	        int sum = 0;
	        int[]arr = new int[n];
	        for(int i=0;i<n;i++){
	            arr[i] = scn.nextInt();
	            sum+=arr[i];
	        }
	        int rem = sum%n;
	        System.out.println(rem*(n-rem));
	    }
	}
}
