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

int main() {
	int T;
	cin >> T;
	for( int i = 0; i < T; i++ ) {
		double p;
		int K;
		cin >> p >> K;
		double ans = K;
		if( p ) {
			ans = (1 - pow( 1 - p, K )) / p;
		}
		cout << fixed << setprecision(12) << ans << endl;
	}
}