#include<vector>
using namespace std;

typedef vector<pair<int,int> >::iterator it;
 

#define MaxN 110000

#define ld long double

#define ll long double

int N;

ld Suma = 0;
int Fii[MaxN],viz[MaxN];

ll Suma = 0;
int T[MaxN],Fii[MaxN],viz[MaxN];

vector<pair<int,int> > A[MaxN];

inline void parcurgere(int nod)

inline void DF(int nod)

{
    viz[nod] = 1;
    Fii[nod] = 1;

    for(it i=A[nod].begin();i<A[nod].end();i++)
        if(!viz[i->first])

    for(int i=0;i<A[nod].size();i++)
        if(!viz[A[nod][i].first])

        {

            parcurgere(i->first);
            Fii[nod] += Fii[i->first];

            DF(A[nod][i].first);
            T[A[nod][i].first] = nod;
            Fii[nod] += Fii[A[nod][i].first];

            Suma += (ld)(i->second)*Fii[i->first]*(N-Fii[i->first]);

            Suma += (ll)(A[nod][i].second)*Fii[A[nod][i].first]*(N-Fii[A[nod][i].first]);

        }
}
int main()
{
    int T;

    cin >> T;

    scanf("%d",&T);

    for(int i=1;i<=T;i++)
    {
        citire();

        parcurgere(0);

        DF(0);

        cout << Suma/((ld)N*(N-1)/2) << "\n";

        printf("%lf\n",(double)(Suma/((ll)N*(N-1)/2)));

        sterge();
    }
}