#include <bits/stdc++.h>
using namespace std;

int main(){
	int t;
	cin >> t;
	cout << fixed << setprecision(11);
	while(t--){
		double p;
		int k;
		cin >> p >> k;
		//公比数列の和：1+(1-p)+(1-p)^2+...+(1-p)^(k-1)
		double r=1-p;
		cout << (1-pow(r,k))/p << endl;
	}
}