#include <bits/stdc++.h>
using namespace std;
struct unionfind{
  vector<int> p;
  vector<long long> S;
  vector<double> R;
  vector<bool> C;
  unionfind(int N, vector<long long> &S, vector<double> &R, vector<bool> &C): S(S), R(R), C(C){
    p = vector<int>(N, -1);
  }
  int root(int x){
    if (p[x] < 0){
      return x;
    } else {
      p[x] = root(p[x]);
      return p[x];
    }
  }
  bool same(int x, int y){
    return root(x) == root(y);
  }
  void unite(int x, int y){
    x = root(x);
    y = root(y);
    if (x != y){
      if (p[x] > p[y]){
        swap(p[x], p[y]);
      }
      p[x] += p[y];
      p[y] = x;
      S[x] += S[y];
      R[x] += R[y];
      if (C[y]){
        C[x] = true;
      }
    }
  }
  double cost(int x){
    x = root(x);
    if (C[x]){
      return 0;
    } else {
      return S[x] * S[x] / R[x];
    }
  }
};
int main(){
  cout << fixed << setprecision(20);
  int N;
  cin >> N;
  vector<int> A(N);
  for (int i = 0; i < N; i++){
    cin >> A[i];
  }
  vector<int> B(N);
  for (int i = 0; i < N; i++){
    cin >> B[i];
  }
  vector<int> P(N);
  for (int i = 0; i < N; i++){
    cin >> P[i];
  }
  vector<long long> D(N);
  for (int i = 0; i < N; i++){
    D[i] = A[i] - B[i];
  }
  vector<double> R(N, 1);
  for (int i = 0; i < N; i++){
    if (P[i] != 0){
      R[i] = (double) 1 / P[i];
    }
  }
  vector<bool> zero(N, false);
  for (int i = 0; i < N; i++){
    if (P[i] == 0){
      zero[i] = true;
    }
  }
  unionfind UF(N, D, R, zero);
  double ans = 0;
  for (int i = 0; i < N; i++){
    ans += UF.cost(i);
  }
  int Q;
  cin >> Q;
  for (int i = 0; i < Q; i++){
    int X, Y;
    cin >> X >> Y;
    X--;
    Y--;
    if (!UF.same(X, Y)){
      ans -= UF.cost(X);
      ans -= UF.cost(Y);
      UF.unite(X, Y);
      ans += UF.cost(X);
    }
    cout << ans << endl;
  }
}