#include <iostream>
#include <iomanip>
#include <cmath>
using namespace std;

int main() {
  cout << setprecision(7);
  int T;
  cin >> T;
  while(T--){
    double p;
    int K;
    cin >> p >> K;
    if(p != 0) p = (p * (1.0 + 1.0e-12) + 1.0e-12);
    if(p == 0){ cout << K << "\n"; }
    else{
      double ans = (1.0 - pow(1.0 - p, K)) / p;
      cout << ans << "\n";
    }
  }
  return 0;
}