#include <bits/stdc++.h>
using namespace std;
template <class TH>
void _dbg(const char *sdbg, TH h) {
  cerr << sdbg << "=" << h << "\n";
}
template <class TH, class... TA>
void _dbg(const char *sdbg, TH h, TA... a) {
  while (*sdbg != ',') cerr << *sdbg++;
  cerr << "=" << h << ",";
  _dbg(sdbg + 1, a...);
}
const long long N = 207;
const long long LOG = 31;
long long test;
long long n, q;
vector<pair<long long, long long> > g;
long double dp[LOG][N][N];
long double ile[N];
long double ile1[N][N];
long long cou;
vector<long long> proste[N * N];
long long czy[N][N];
long double wsiebie[N];
long double wek[N];
long long ilo(pair<long long, long long> a, pair<long long, long long> b,
              pair<long long, long long> c) {
  b.first -= a.first;
  b.second -= a.second;
  c.first -= a.first;
  c.second -= a.second;
  return b.first * c.second - b.second * c.first;
}
void matrix_multi(long long x) {
  for (long long i = 0; i < (n); ++i) {
    for (long long l = 0; l < (n); ++l) {
      for (long long j = 0; j < (n); ++j) {
        dp[x][i][j] += dp[x - 1][i][l] * dp[x - 1][l][j];
      }
    }
  }
}
void dodej(long long x) {
  long double pom[N];
  for (long long i = 0; i < (n); ++i) {
    pom[i] = 0;
  }
  for (long long i = 0; i < (n); ++i) {
    for (long long j = 0; j < (n); ++j) {
      pom[i] += dp[x][i][j] * wek[j];
    }
  }
  for (long long i = 0; i < (n); ++i) {
    wek[i] = pom[i];
  }
}
void multi(long long x) {
  long long j = 0;
  while (x) {
    if (x % 2) {
      dodej(j);
    }
    x /= 2;
    j++;
  }
  return;
}
void solve() {
  cin >> n;
  for (long long i = 1; i <= (n); ++i) {
    long long x, y;
    cin >> x >> y;
    g.emplace_back(x, y);
  }
  for (long long i = 0; i < (n); ++i) {
    for (long long j = 0; j < (n); ++j) {
      if (czy[i][j] == 0 && i != j) {
        cou++;
        proste[cou].push_back(i);
        proste[cou].push_back(j);
        for (long long l = 0; l < (n); ++l) {
          if (i == j || i == l || j == l) continue;
          if (ilo(g[i], g[j], g[l]) == 0) {
            proste[cou].push_back(l);
          }
        }
        for (auto it : proste[cou]) {
          ile[it]++;
          for (auto it1 : proste[cou]) {
            czy[it][it1] = 1;
          }
        }
      }
    }
  }
  for (long long i = 0; i < (n); ++i) {
    for (long long j = 0; j < (n); ++j) {
      for (long long l = 0; l < (n); ++l) {
        if (i == j) {
          continue;
        }
        ile1[i][j] += (ilo(g[i], g[j], g[l]) == 0);
      }
    }
  }
  for (long long i = 1; i <= (cou); ++i) {
    for (auto it : proste[i]) {
      wsiebie[it] += 1.0 / (long double)proste[i].size();
    }
  }
  for (long long i = 0; i < (n); ++i) {
    for (long long j = 0; j < (n); ++j) {
      if (i == j) {
        dp[0][i][j] = 1.0 * (long double)wsiebie[i] / (long double)ile[i];
      } else {
        dp[0][i][j] = 1.0 / (long double)ile[i] / (long double)ile1[i][j];
      }
    }
  }
  for (long long i = 1; i <= (20); ++i) {
    matrix_multi(i);
  }
  cin >> q;
  for (long long i = 1; i <= (q); ++i) {
    long long a, b;
    cin >> a >> b;
    a--;
    b--;
    for (long long j = 0; j < (n); ++j) {
      wek[j] = j == a;
    }
    multi(b);
    long double res = 0;
    for (long long j = 1; j <= (cou); ++j) {
      long double xx = 0;
      for (auto it : proste[j]) {
        xx += wek[it];
      }
      res = max(res, xx / proste[j].size());
    }
    cout << res << '\n';
  }
  return;
}
int32_t main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  cout.precision(10);
  cout << fixed;
  test = 1;
  for (long long i = 1; i <= test; i++) {
    solve();
  }
  return 0;
}
