#include<cstdio>
#include<cstring>
#include<algorithm>
#include<iostream>
#include<map>
using namespace std;
struct node{
	int s,nex;
}a[1010];
struct edge{
	int y,v,nex;
}e[5000];
int n,m,x,y,v;
int p;
int i;
int T;
double f[1001];
int W[1001];
int D[1001];
void add(int x,int y,int v)
{
	m++;
	a[x].s++;
	e[m].y=y;
	e[m].v=v;
	e[m].nex=a[x].nex;
	a[x].nex=m;
}
void dfs(int s)
{
	int t=a[s].nex;
	for (int i=1;i<=a[s].s;i++)
	{
		D[e[t].y]=D[s]+1;
		W[e[t].y]=W[s]+e[t].v;
		dfs(e[t].y);
		t=e[t].nex;
	}
}
int main()
{
	freopen("treec.in","r",stdin);
	freopen("treec.out","w",stdout);
	scanf("%d",&T);
	for (int II=1;II<=T;II++)
	{
		memset(a,0,sizeof(a));
		memset(e,0,sizeof(e));
		
		scanf("%d",&n);
		p=0;
		for (i=1;i<n;i++)
		{
			scanf("%d%d%d",&x,&y,&v);
			add(x,y,v);
		}
		dfs(0);
		for (i=1;i<n;i++)
			f[i]=(double)W[i]/(double)D[i];
		double maxn=0;
		for (i=1;i<n;i++)
			if (f[i]-maxn>0.000001) maxn=f[i];
		printf("%.3lf\n",maxn);
		
	}
	return 0;
}