#include <bits/stdc++.h>
using namespace std;
const int MOD = 1000000007;
inline int gcd(int a, int b) { return b ? gcd(b, a % b) : a; }
inline int lcm(int a, int b) { return a * b / gcd(a, b); }
inline int add(int a, int b) { return ((a % MOD) + (b % MOD)) % MOD; }
inline int multi(int a, int b) { return ((a % MOD) * (b % MOD)) % MOD; }
inline int sub(int a, int b) {
  a %= MOD;
  b %= MOD;
  a -= b;
  if (a < 0) a += MOD;
  return a;
}
bool isPrime(int x) {
  if (x <= 4 || x % 2 == 0 || x % 3 == 0) return x == 2 || x == 3;
  for (int i = 5; i * i <= x; i += 6) {
    if (x % i == 0 || x % (i + 2) == 0) {
      return 0;
    }
  }
  return 1;
}
long long prime[1000002];
int Prime(int a) {
  for (int i = 2; i <= a / 2; ++i) {
    if (a % i == 0) {
      return 0;
    }
  }
  return 1;
}
void sieve() {
  for (int i = 0; i <= 1000001; i++) prime[i] = 0;
  int maxn = 1000001;
  for (int i = 2; i <= maxn; i++) {
    if (prime[i] == 0) {
      for (int j = i; j <= maxn; j += i) {
        prime[j]++;
      }
    }
  }
}
int ceilIndex(vector<int> a, int l, int h, int find) {
  while (l < h) {
    int m = (l + h) / 2;
    if (a[m] >= find)
      h = m;
    else
      l = m + 1;
  }
  return h;
}
void run_fun() {
  int n;
  cin >> n;
  int s = 0, in;
  for (int i = 0; i < n; i++) {
    cin >> in;
    s += in;
  }
  int fir = s % n;
  int sec = (n - s % n);
  cout << fir * (sec) << endl;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  int t;
  cin >> t;
  while (t--) run_fun();
  return 0;
}
