import java.io.*;
import java.util.Arrays;
import java.util.StringTokenizer;

public class Codeforces {

    static int dx[] = {1, -1, 0, 0, 1, 1, -1, -1};
    static int dy[] = {0, 0, -1, 1, -1, 1, -1, 1};

    public static boolean inRange(int x, int n) {
        return (x >= 0) && (x < n);
    }

    public static void main(String[] args) throws IOException {
        Scanner in = new Scanner(System.in);
        PrintWriter out = new PrintWriter(System.out);
        //////////////////////////////////

        int t = in.nextInt();
        for (int i = 0; i < t; i++) {
            int n = in.nextInt();
            long ar[] = in.nextLongArray(n);
            long one = Arrays.stream(ar).sum()%n;
            out.println(one *(n-one));
        }

        //////////////////////////////////
        out.flush();
        out.close();
    }

    static class Scanner {

        private final BufferedReader reader;
        private StringTokenizer tokenizer;

        public Scanner(InputStream stream) {
            int bufferSize = 32 * 1024;
            reader = new BufferedReader(new InputStreamReader(stream), bufferSize);
            tokenizer = null;
        }

        public String next() {
            while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return tokenizer.nextToken();
        }

        public String nextLine() {
            if (true) {
                throw new RuntimeException("nextLine: not tested");
            }
            while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            StringBuilder sb = new StringBuilder();
            return tokenizer.nextToken("\n");
        }

        public int nextInt() {
            return Integer.parseInt(next());
        }

        public long nextLong() {
            return Long.parseLong(next());
        }

        public int[] nextIntArray(int n) {
            int[] arr = new int[n];
            for (int i = 0; i < n; i++) {
                arr[i] = nextInt();
            }
            return arr;
        }

        public long[] nextLongArray(int n) {
            long[] arr = new long[n];
            for (int i = 0; i < n; i++) {
                arr[i] = nextLong();
            }
            return arr;
        }

        public String[] nextStringArray(int n) {
            String[] arr = new String[n];
            for (int i = 0; i < n; i++) {
                arr[i] = next();
            }
            return arr;
        }


        public int[][] nextIntArrayTwoDimension(int n, int m) {
            int[][] arr = new int[n][m];
            for (int i = 0; i < n; i++) {
                arr[i] = nextIntArray(m);
            }
            return arr;
        }

        public long[][] nextLongArrayTwoDimension(int n, int m) {
            long[][] arr = new long[n][m];
            for (int i = 0; i < n; i++) {
                arr[i] = nextLongArray(m);
            }
            return arr;
        }

        public char[][] nextGridString(int n) {
            char[][] map = new char[n][];
            for (int i = 0; i < n; i++) {
                map[i] = next().toCharArray();
            }
            return map;
        }
    }
}