#include<bits/stdc++.h>

using namespace std;
 
#define ff              first
#define ss              second
#define ll             long long
#define loop(i,a,b)      for(long long int i=a;i<b;i++)
#define loopr(i,a,b)     for(long long int i=a;i>=b;i--)
#define pb              push_back
#define mp              make_pair
#define pii             pair<int,int>
#define vi              vector<int>
#define mii             map<int,int>
#define pqb             priority_queue<int>
#define pqs             priority_queue<int,vi,greater<int> >
#define setbits(x)      __builtin_popcountll(x)
#define zrobits(x)      __builtin_ctzll(x)
#define mod             1000000007
#define inf             1e18
#define ps(x,y)         fixed<<setprecision(y)<<x
#define mk(arr,n,type)  type *arr=new type[n];
#define w(x)            int x; cin>>x; while(x--)
mt19937                 rng(chrono::steady_clock::now().time_since_epoch().count());
 
 
 int power(long long x, unsigned int y, int p)
{
    int res = 1;     // Initialize result
 
    x = x % p; // Update x if it is more than or
                // equal to p
  
    if (x == 0) return 0; // In case x is divisible by p;
 
    while (y > 0)
    {
        // If y is odd, multiply x with result
        if (y & 1)
            res = (res*x) % p;
 
        // y must be even now
        y = y>>1; // y = y/2
    
        x = (x*x) % p;
    }
    return res;
}


 
int main()
{ 
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    ll t;
    cin>>t;
    while(t--){
       ll n;
       cin>>n;
       ll a[n];
      ll ans=0;
       loop(i,0,n){
        cin>>a[i];
        ans+=a[i];
    }
     
       
       //ll ans=accumulate(a,a+n,0);
  
       ll x=ans/n;
       ll dif=ans-(x*n);
       cout<<dif*(n-dif)<<endl;
  
    }
   
}