#include <bits/stdc++.h>
using namespace std;
struct point {
  long long x, y;
  point(long long X = 0, long long Y = 0) : x(X), y(Y) {}
};
bool colinear(point a, point b, point c) {
  return (a.x - c.x) * (b.y - c.y) - (a.y - c.y) * (b.x - c.x) == 0;
}
const int maxn = 201, logm = 14;
int n, q;
vector<vector<long double> > mul(vector<vector<long double> >& a,
                                 vector<vector<long double> >& b) {
  vector<vector<long double> > m(n, vector<long double>(n, 0.));
  for (int i = 0; i < n; i++)
    for (int j = 0; j < n; j++)
      for (int k = 0; k < n; k++) m[i][j] += a[i][k] * b[k][j];
  return m;
}
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout << fixed << setprecision(10);
  cin >> n;
  vector<point> p(n);
  for (int i = 0; i < n; i++) cin >> p[i].x >> p[i].y;
  vector<vector<vector<long double> > > t(
      logm, vector<vector<long double> >(n, vector<long double>(n, 0.)));
  for (int i = 0; i < n; i++) {
    vector<vector<int> > lines;
    for (int j = 0; j < n; j++) {
      if (i == j) continue;
      int l = -1;
      for (int k = 0; k < lines.size(); k++) {
        if (colinear(p[i], p[j], p[lines[k][1]])) {
          l = k;
          break;
        }
      }
      if (l == -1)
        lines.push_back({i, j});
      else
        lines[l].push_back(j);
    }
    for (int j = 0; j < lines.size(); j++)
      for (int k : lines[j])
        t[0][i][k] += (1. / (long double)(lines.size())) *
                      (1. / (long double)(lines[j].size()));
  }
  for (int i = 1; i < logm; i++) t[i] = mul(t[i - 1], t[i - 1]);
  vector<vector<int> > lines, num(n, vector<int>(n, -1));
  for (int i = 0; i < n; i++) {
    for (int j = i + 1; j < n; j++) {
      if (num[i][j] != -1) continue;
      lines.push_back({i, j});
      for (int iter = 1; iter < lines.back().size(); iter++)
        for (int k = lines.back()[iter] + 1; k < n; k++) {
          if (colinear(p[lines.back()[iter - 1]], p[lines.back()[iter]],
                       p[k])) {
            lines.back().push_back(k);
            break;
          }
        }
      for (int p1 : lines.back())
        for (int p2 : lines.back()) num[p1][p2] = 1;
    }
  }
  cin >> q;
  while (q--) {
    int target, m;
    cin >> target >> m;
    vector<long double> v(n, 0.);
    v[--target] = 1.;
    for (int i = 0; i < logm; i++)
      if ((1 << i) & (m - 1)) {
        vector<long double> v2(n, 0.);
        for (int x = 0; x < n; x++)
          for (int y = 0; y < n; y++) v2[x] += t[i][x][y] * v[y];
        v = v2;
      }
    long double ans = 0.;
    for (int i = 0; i < lines.size(); i++) {
      long double sum = 0.;
      for (int j : lines[i]) sum += v[j];
      sum /= (long double)(lines[i].size());
      ans = max(ans, sum);
    }
    cout << ans << "\n";
  }
  return 0;
}
