#include<bits/stdc++.h>
#define FIN freopen("./1004.in","r",stdin)
#define debug(x) cout<<#x"=["<<x<<"]"<<endl
using namespace std;
typedef long long ll;
const ll maxn(1e5+5);
const double pi=acos(-1);
struct car{
    ll l,s,v;
    double t;
}c[maxn];
double ans;
ll n,sum[maxn];
int main(){
#ifndef ONLINE_JUDGE
    FIN;
#endif
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    while(cin>>n){
        ans=0;
        sum[0]=0;
        for(ll i=1;i<=n+1;i++){
            cin>>c[i].l;
            sum[i]=sum[i-1]+c[i].l;
        }
        for(ll i=1;i<=n+1;i++){
            cin>>c[i].s;
            c[i].s+=sum[i]-c[1].l;
        }
        for(ll i=1;i<=n+1;i++){
            cin>>c[i].v;
            c[i].t=(c[i].s+0.0)/c[i].v;
            ans=max(ans,c[i].t);
        }
        cout<<fixed<<setprecision(10)<<ans<<endl;
    }
}

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const ll INF(0x3f3f3f3f3f3f3f);
const double ESP(1e-9);
const ll mod(998244353);
#define per(i, a, b) for(int i=a; i<b; i++)
#define rep(i, a, b) for(int i=b-1; i>=a; i--)
#define mem(a, b) memset(a, b, sizeof(a))
ll powmod(ll a, ll b) { ll res = 1; a %= mod; assert(b >= 0); for (; b; b >>= 1) { if (b & 1)res = res * a%mod; a = a * a%mod; }return res; }
ll gcd(ll a, ll b) { return b ? gcd(b, a%b) : a; }

const int MAXN(1e4 + 7);
int T, n, m;
struct spfa {
    int head1[MAXN], nxt1[2*MAXN];
    int to[2*MAXN];
    ll val[2*MAXN];
    ll len[MAXN];
    int vis[MAXN];
    queue<int> Q;
    int cnt1;
    spfa(int n=0, int m=0) {
        per(i, 1, n+1) {
            head1[i]=0;
        }
        per(i, 1, m+1) {
            nxt1[i]=0;
        }
        cnt1 = 1;
    }
    void init(int n=0, int m=0) {
        per(i, 1, n+1) {
            head1[i]=0;
        }
        per(i, 1, m+1) {
            nxt1[i]=0;
        }
        cnt1 = 1;
    }
    void add(int u, int v, int w) {
        nxt1[cnt1] = head1[u];
        head1[u] = cnt1;
        to[cnt1] = v;
        val[cnt1++] = w;
    }
    void SPFA(int s) {
        per(i, 1, n+1) {
            len[i] = INF;
            vis[i] = 0;
        }
        vis[s] = 1;
        len[s] = 0;
        Q.push(s);

        while (!Q.empty()) {
            s = Q.front();
            Q.pop();
            vis[s] = 0;
            for(int it=head1[s]; it; it=nxt1[it]) {
                if(len[to[it]]>len[s]+val[it]) {
                    len[to[it]]=len[s]+val[it];
                    if(!vis[to[it]]) {
                        Q.push(to[it]);
                        vis[to[it]] = 1;
                    }
                }
            }
        }
    }
}SS;

class Dinic {
public:
    int N, S, T;
    vector<int> head;   //存每个点最后一条边
    vector<int> cur;    //当前弧优化，进一步加速
    vector<int> depth;  //存每次bfs后每个点的深度
    vector<int> nxt;    //存每条边的前一条边
    vector<int> To;     //存每条边连接的另一个点
    vector<ll> Val;    //存每条边的权重
    ll outt;           //存最大流

public:
    Dinic(int Nn=0, int Ss=0, int Tt=0): N(Nn), S(Ss), T(Tt) {
        head.assign(N+1, 0);
        depth.resize(N+1);
        Val.resize(2);
        To.resize(2);
        nxt.resize(2);
    }
    void init(int Nn=0, int Ss=0, int Tt=0) {
        N=Nn, S=Ss, T=Tt;
        head.assign(N+1, 0);
        depth.resize(N+1);
        Val.resize(2);
        To.resize(2);
        nxt.resize(2);
    }
    void _Add(int u, int v, ll w) {
        nxt.push_back(head[u]);
        head[u] = To.size();
        To.push_back(v);
        Val.push_back(w);
    }
    void addEdge(int u, int v, ll w) {
        _Add(u, v, w);
        _Add(v, u, 0);
    }
    int bfs() {
        queue<int> qq;
        qq.push(S);
        vector<int> marked;
        marked.assign(N+1, 0);
        marked[S] = 1;
        marked[T] = depth[S] = 0;
        int tmp;

        while(!qq.empty()) {
            tmp = qq.front();
            qq.pop();
            for(int i=head[tmp]; i; i=nxt[i]) {
                if(Val[i] && !marked[To[i]]) {
                    marked[To[i]] = 1;
                    depth[To[i]] = depth[tmp]+1;
                    qq.push(To[i]);
                }
            }
        }
        if(marked[T]) {
            return 1;
        }
        return 0;
    }
    int dfs(int pos, ll val) {
        if(pos==T) {
            return val;
        }
        for(int& i=cur[pos]; i; i=nxt[i]) {     //利用当前弧，&饮用保证当前弧能被修改
            if(Val[i] && depth[To[i]]==depth[pos]+1) {
                ll valu = dfs(To[i], min(val, Val[i]));
                if(valu) {
                    Val[i] -= valu;
                    Val[i^1] += valu;
                    return valu;
                }
            }
        }
        return 0;
    }
    void dinic() {
        outt = 0;
        while(bfs()) {
            cur = head;     //赋值当前弧
            ll val;
            while((val=dfs(S, INF))) {
                outt += val;
            }
        }
    }
}DD;

int marked[MAXN];
void dfs(int pos) {
    marked[pos] = 1;
    for(int it=SS.head1[pos]; it; it=SS.nxt1[it]) {
        if(SS.len[SS.to[it]]==SS.len[pos]+SS.val[it]) {
            DD.addEdge(pos, SS.to[it], SS.val[it]);
            if(!marked[SS.to[it]]) {
                dfs(SS.to[it]);
            }
        }
    }
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);

    cin >> T;
    while(T--) {
        cin >> n >> m;
        SS.init(n, m);
        int u, v, w;
        per(i, 0, m) {
            cin >> u >> v >> w;
            SS.add(u, v, w);
        }
        SS.SPFA(1);
        DD.init(n, 1, n);
        per(i, 1, n+1) {
            marked[i]=0;
        }
        dfs(1); //建网络流边
        DD.dinic();
        cout << DD.outt << endl;
    }

    return 0;
}