#include <bits/stdc++.h>
using namespace std;
int gi() {
  char ch = '!';
  int res = 0, f = 0;
  while (ch < '0' || ch > '9') {
    ch = getchar();
    if (ch == '-') f = 1;
  }
  while (ch >= '0' && ch <= '9') res = res * 10 + ch - '0', ch = getchar();
  return f ? -res : res;
}
const int N = 1e5 + 7;
int n, Q, arr[N], cur[N];
double f[N][110], ans;
int main() {
  n = gi();
  for (int i = 1; i <= n; ++i) {
    arr[i] = gi(), f[i][arr[i]] = 1, cur[i] = arr[i];
    ans += f[i][0];
  }
  Q = gi();
  for (int i = 1; i <= Q; ++i) {
    int u = gi(), v = gi(), x = gi();
    ans -= f[u][0];
    for (int k = 1; k <= x; ++k) {
      for (int j = 0; j <= arr[u]; ++j) {
        if (j > cur[u])
          f[u][j] = 0;
        else {
          f[u][j] = (cur[u] - j) / (double)cur[u] * f[u][j];
          if (j + 1 <= cur[u])
            f[u][j] += (j + 1) / (double)cur[u] * f[u][j + 1];
        }
      }
      --cur[u];
    }
    cur[v] += x;
    ans += f[u][0];
    printf("%.10lf\n", ans);
  }
  return 0;
}
