#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
  #include "settings/debug.cpp"
  #define _GLIBCXX_DEBUG
#else
  #define Debug(...) void(0)
#endif
#define rep(i, n) for (int i = 0; i < (n); ++i)
using ll = long long;
using ull = unsigned long long;

int main() {
  int t;
  cin >> t;
  cout << fixed << setprecision(15);
  while (t--) {
    double p;
    int k;
    cin >> p >> k;
    if (p == 0)
      cout << k << endl;
    else
      cout << (1 - pow(1 - p, k)) / p << endl;
  }
  return 0;
}