#include <iostream>
#include <stdio.h>
#include <cstring>
#include <algorithm>
#include <math.h>
using namespace std;
#define FOR(i,j,k) for(int i=j;i<=k;i++)
#define ll long long
#define maxn 4004
#define eps 1e-1
double a[10010];
double b[10010];
int main()
{
    int T;
    scanf("%d",&T);
    while(T--)
    {
        int n;
        scanf("%d",&n);
        double Max=0;
        FOR(i,1,n)
        scanf("%lf",&a[i]),Max=max(a[i],Max);
        FOR(i,1,n)
        scanf("%lf",&b[i]);
        double l=0.0,r=Max;
        double m=(l+r)/2.0;
        while(l+0.000001<r)
        {
            
            double sum1=0,sum2=0;
            m=(l+r)/2.0;
            FOR(i,1,n)
            {
                if((a[i]-m)>=0)
                {
                sum1+=(a[i]-m)*(a[i]-m)*(a[i]-m)*b[i]*b[i]/(a[i]*a[i]*3);
                sum2+=a[i]*b[i]*b[i]/3-(a[i]-m)*(a[i]-m)*(a[i]-m)*b[i]*b[i]/(a[i]*a[i]*3);
                }
                else
                    sum2+=a[i]*b[i]*b[i]/3;
            }
            //cout<<m<<" "<<sum1<<" "<<sum2<<endl;
            if(sum1>sum2)
            l=m;
            else r=m;
        }
        int ans=m;
        printf("%d\n",ans);
    }
    return 0;
}