#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef long double ld;
#define mems(p) memset(p,-1,sizeof(p))
#define pb push_back
#define eb emplace_back
#define nl "\n"
#define sz(x) (int)(x).size()
#define all(x) x.begin(), x.end()
#define allr(x) x.rbegin(), x.rend()

using pi = pair<int,int>;
using pl = pair<ll,ll>;
using vi = vector<int>;
using vl = vector<ll>;
using vb = vector<bool>;
using vd = vector<double>;
using vc = vector<char>;
using vpi = vector<pi>;
using vpl = vector<pl>;
using vvi = vector<vector<int>>;
using vvl = vector<vector<ll>>;
using vvb = vector<vector<bool>>;
using vvd = vector<vector<double>>;
using vvc = vector<vector<char>>;
using vvpi = vector<vector<pi>>;
using vvpl = vector<vector<pl>>;
using vvvi = vector<vector<vector<int>>>;
using vvvl = vector<vector<vector<ll>>>;
using vvvb = vector<vector<vector<bool>>>;
using vvvd = vector<vector<vector<double>>>;
using vvvc = vector<vector<vector<char>>>;
using vvvpi = vector<vector<vector<pi>>>;
using vvvpl = vector<vector<vector<pl>>>;

const int mxN = 8e5 + 100;
const ll MOD = 1e9 + 7;

void fast()
{ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);}

ll gcd(ll a, ll b) {
    return b ? gcd(b, a%b) : a;
}

vl factorial;

ll expo(ll x, ll exp, ll mod = MOD) {
    if (exp <= 0) return 1;
    ll tmp = (x*x) % mod;
    if (exp%2) {
        return (expo(tmp, exp/2, mod) * x) % mod;
    }
    return (expo(tmp, exp/2, mod)) % mod;
}

ll choice(ll n, ll r, ll mod = MOD) {
    if (n < r) return 0;
    ll numer = factorial[n];
    ll denom = (factorial[r] * factorial[n-r]) % mod;
    return numer * expo(denom, mod - 2, mod) % mod;
}

ll phi(ll n) {
    ll result = n;
    for (ll i = 2; i * i <= n; i++) {
        if (n % i == 0) {
            while (n % i == 0)
                n /= i;
            result -= result / i;
        }
    }
    if (n > 1)
        result -= result / n;
    return result;
}

int main() {
    fast();
    int t;
    cin >> t;
    while (t--) {
        ll n;
        cin >> n;
        ll sum = 0;
        for (int i = 0; i < n; ++i)
        {
            ll x;
            cin >> x;
            sum += x;
        }

        ll each = sum/n;
        ll rem = sum - each*n;
        ll ans = rem * (n-rem);
        cout << ans << nl;
    }
}









