import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.StringTokenizer;

public class pre19 {
    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 obj = new FastReader();
        int tc = obj.nextInt();
        while(tc--!=0){
            int n = obj.nextInt(),arr[] = new int[n];
            long sum = 0;
            for(int i=0;i<n;i++) sum += arr[i] = obj.nextInt();
            long div = sum/n,mod = sum%n;
            System.out.println(mod*(n-mod));
        }
    }
}
