//package Practice;
import java.io.*;
import java.util.*;


public class codefor
{
	static class FastReader 
    { 
        BufferedReader br; 
        StringTokenizer st; 
  
        public FastReader() 
        { 
            br = new BufferedReader(new
                     InputStreamReader(System.in)); 
        }
        String next() 
        { 
            while (st == null || !st.hasMoreElements()) 
            { 
                try
                { 
                    st = new StringTokenizer(br.readLine()); 
                }
                catch (IOException  e) 
                { 
                    e.printStackTrace(); 
                } 
            } 
            return st.nextToken(); 
        } 
  
        int nextInt() 
        { 
            return Integer.parseInt(next()); 
        } 
  
        long nextLong() 
        { 
            return Long.parseLong(next()); 
        } 
  
        double nextDouble() 
        { 
            return Double.parseDouble(next()); 
        } 
  
        String nextLine() 
        { 
            String str = ""; 
            try
            { 
                str = br.readLine(); 
            } 
            catch (IOException e) 
            { 
                e.printStackTrace(); 
            } 
            return str; 
        }
    }
	public static void main(String[] args) 
	{
		FastReader sc=new FastReader();
		int T=sc.nextInt();
		while(T-->0)
		{
			long n=sc.nextLong(),sum=0;
			int arr[]=new int[(int)n];
			for(int i=0;i<n;i++)
			{
				arr[i]=sc.nextInt();
				sum=sum+arr[i];
			}
			sum=sum%n;
			System.out.println(sum*(n-sum));			
		}
	}
}
















