//
//  main.cpp
//  1001.A-Pyramid Split
//
//  Created by eycia on 12/9/15.
//  Copyright (c) 2015 eycia. All rights reserved.
//

#include <set>
#include <map>
#include <list>
//#include <tuple>
//#include <ratio>
#include <cmath>
#include <queue>
#include <stack>
#include <deque>
#include <cstdio>
#include <string>
#include <vector>
#include <bitset>
#include <iomanip>
#include <sstream>
#include <cstring>
#include <cstdlib>
#include <iostream>
#include <algorithm>
using namespace std;

int n;

int a[10005], b[10005];


double getto(double hi) {
    double tot = 0;
    for (int i = 0; i < n; i++) {
        if (hi < a[i]) {
            double rest = a[i] - hi;
            double radio = rest / a[i];
            tot += b[i]*b[i]*rest/3.0*radio*radio;
        }
    }
    return tot;
}

void work() {
    
    double tot = 0;
    
    int hi = 0;
    
    for (int i = 0; i < n; i++) {
        tot += b[i]*b[i]*a[i]/3.0;
        hi = max(hi, a[i]);
    }

    double le = 0, ri = hi;
    
    for (int i = 0; i < 100; i++) {
        double mi = (le + ri) / 2;
        
        if (getto(mi) < tot*0.5) {
            ri = mi;
        } else {
            le = mi;
        }
    }
    
    printf("%d\n", (int)(le));
}


int main(int argc, const char * argv[]) {
    int t;
    scanf("%d", &t);
    while (t--) {
        scanf("%d", &n);
        for (int i = 0; i < n; i++) {
            scanf("%d", &a[i]);
        }
        for (int i = 0; i < n; i++) {
            scanf("%d", &b[i]);
        }
        
        work();
        
    }
}