#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <algorithm>
#include <cmath>
#include <map>
#include <set>
#include <vector>
#include <queue>
#include <iostream>
#include <cassert>
#include <bitset>
#include <ctime>

using namespace std;

typedef long long LL;
typedef double DB;
typedef pair<int, int> PII;
typedef vector<int> VI;
typedef vector<PII> VPII;

#define X first
#define Y second
#define pb push_back
#define bit(n) (1 << (n))
#define count(n) (__builtin_popcount(n))
#define countl(n) (__builtin_popcountll(n))

template<class T>
inline void chkmin(T &x, T y) {
    if (y < x) x = y;
}

template<class T>
inline void chkmax(T &x, T y) {
    if (x < y) x = y;
}

const int MN = 100005;
int A[MN], B[MN];

inline DB calc(DB x, DB h) {
    return x * x * h;    
}

int main() {
    
    
    int n;
    int tn;
    
    for (cin >> tn; tn--; ) {
        scanf("%d", &n);
        DB en = 0, st = 0, mid, tot = 0;
        for (int i = 0; i < n; i++) scanf("%d", A + i), chkmax(en, 1.0 * A[i]);
        for (int i = 0; i < n; i++) scanf("%d", B + i);
        for (int i = 0; i < n; i++) {
            tot += calc(B[i], A[i]);
        }
        for (int i = 0; i < 50; i++) {
            mid = (st + en) / 2;
            DB sum = 0;
            for (int j = 0; j < n; j++) {
                if (mid < A[j]) sum += calc(B[j] * (A[j] - mid) / (DB)A[j], A[j] - mid);
            }
            if (sum < 0.5 * tot) en = mid;
            else st = mid;
        }
        printf("%d\n", int(mid));
    }
    
    return 0;    
}