#include "testlib.h"

#include <cstdio>
#include <string>
using namespace std;

const int maxK = 10'000'000;

int main() {
  registerValidation();
  
  int T = inf.readInt(1,1000,"T");
  inf.readEoln();

  for(int testcase_id=1; testcase_id<=T; testcase_id++){
    std::string testcase_id_s = " for testcase " + vtos(testcase_id);
    double p = inf.readStrictReal(0.0,1.0,1,10,"p"+testcase_id_s);
    inf.readSpace();
    int K = inf.readInt(0,maxK,"K"+testcase_id_s);
    inf.readEoln();

		if(p == 0){
			printf("%d\n",K);
		}
		else{
			double ans = (1.0-pow(1.0-p,K)) / p;
			printf("%.12f\n",ans);
		}
  }

  inf.readEof();
  return 0;
}