#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;

ll Suma = 0;

int T[MaxN],Fii[MaxN],viz[MaxN];
vector<pair<int,int> > A[MaxN];

    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])

        {

            DF(i->first);
            T[i->first] = nod;
            Fii[nod] += Fii[i->first];
        }
}

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

inline double suma(void)
{
    ld sum = 0;
 
    for(int i=0;i<=N;i++)
        for(it j=A[i].begin();j<A[i].end();j++)
            if(j->first > i)
            {
                if(T[i] != j->first)
                    sum += (ld)j->second*Fii[j->first]*(N-Fii[j->first]);
                else
                    sum += (ld)j->second*Fii[i]*(N-Fii[i]);
            }
 
    return sum/((ld)N*(N-1)/2);

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

}
inline void sterge(void)
{
    for(int i=0;i<N;i++)

        A[i].clear(), Fii[i] = T[i] = viz[i] = 0;

        A[i].clear(), Fii[i] = T[i] = viz[i] = Suma = 0;

}
int main()
{

    //freopen("test.txt","r",stdin);

    int T;
    scanf("%d",&T);

        citire();
        DF(0);

        printf("%lf\n",suma());

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

        sterge();
    }