#include<stdio.h>#include<string.h>#include<math.h>#include<stdlib.h>#define MAXD 1010#define MAXM 1000010int N, x[MAXD], y[MAXD], people[MAXD], a[MAXM], b[MAXM], M, e, r[MAXM];int first[MAXD], next[2 * MAXD], v[2 * MAXD], vis[MAXD], p[MAXD];double w[MAXM], maxlen[MAXD][MAXD], total, len[2 * MAXD];int cmp(const void *_p, const void *_q){int *p = (int *)_p;int *q = (int *)_q;return w[*p] < w[*q] ? -1 : 1;}int find(int x){return p[x] == x ? x : (p[x] = find(p[x]));}double distance(int i, int j){return sqrt((double)(x[i] - x[j]) * (x[i] - x[j]) + (y[i] - y[j]) * (y[i] - y[j]));}void init(){int i, j;    scanf("%d", &N);for(i = 0; i < N; i ++)        scanf("%d%d%d", &x[i], &y[i], &people[i]);    M = 0;for(i = 0; i < N; i ++)for(j = i + 1; j < N; j ++)        {            a[M] = i;            b[M] = j;            w[M] = distance(i, j);            M ++;        }}void add(int x, int y, double z){    v[e] = y;    len[e] = z;    next[e] = first[x];    first[x] = e;    e ++;}void dfs(int fa, int cur, double max){int i;    vis[cur] = 1;for(i = first[cur]; i != -1; i = next[i])if(!vis[v[i]])        {if(len[i] > max)            {                maxlen[fa][v[i]] = len[i];                dfs(fa, v[i], len[i]);            }else            {                maxlen[fa][v[i]] = max;                dfs(fa, v[i], max);            }        }}void prepare(){int i, j, k, tx, ty;for(i = 0; i < M; i ++)        r[i] = i;    qsort(r, M, sizeof(r[0]), cmp);for(i = 0; i < N; i ++)        p[i] = i;    e = 0;    memset(first, -1, sizeof(first));    total = 0;for(i = 0; i < M; i ++)    {        k = r[i];        tx = find(a[k]);        ty = find(b[k]);if(tx != ty)        {            total += w[k];            p[tx] = ty;            add(a[k], b[k], w[k]);            add(b[k], a[k], w[k]);        }    }for(i = 0; i < N; i ++)    {        memset(vis, 0, sizeof(vis));        dfs(i, i, 0);    }}void solve(){int i, j;double temp, res = 0;for(i = 0; i < N; i ++)for(j = i + 1; j < N; j ++)        {            temp = (double)(people[i] + people[j]) / (total - maxlen[i][j]);if(temp > res)                res = temp;        }    printf("%.2f\n", res);}int main(){int t;    scanf("%d", &t);while(t --)    {        init();        prepare();        solve();    }return 0;}