#include <cstdio>
#include <cstring>
#include <algorithm>
#include <iostream>
#include <queue>
#include <cmath>
using namespace std;
#define FOR(i, l, r) for(int i = l; i <= r; i++)
#define REP(i, r, l) for(int i = r; i >= l; i--)
typedef long long ll;
double eps = 1e-6;
const int maxn = 100050;
const int mod = 1e9 + 7;
int d[maxn], h[maxn];
int n;
double Upper(double ht)
{
    double s = 0;
    FOR(i, 0, n-1)
    {
        if(ht > h[i]) continue;
        else s += (h[i] - ht) * (1 - ht / h[i]) * (1 - ht / h[i]) * d[i] * d[i];
    }
    return s;
}

int main()
{
    int cas;
    scanf("%d", &cas);
    while(cas--)
    {
        scanf("%d", &n);
        int R = -1;
        FOR(i, 0, n-1)
            scanf("%d", &h[i]), R = max(R, h[i]);
        FOR(i, 0, n-1)
            scanf("%d", &d[i]);
        ll sum = 0;
        FOR(i, 0, n-1)
            sum += 1ll * d[i] * d[i] * h[i];
        double r = R, l = 0;
        while(l + eps < r){
            double mid = (l + r)/2;
            if(Upper(mid) * 2 > sum) l = mid;
            else r = mid;
        }
        double ans = 0, ht = l;
        printf("%.0f\n", floor(l));
        // FOR(i, 0, n-1)
        // {
        //     if(h[i] < l) continue;    
        //     else  ans += (1 - ht / h[i]) * (1 - ht / h[i]) * d[i] * d[i];
        // }
        // printf("%.0f\n", ans);
    }

    return 0;
}