UVA 12457

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

const int OO = 1e9;
const double EPS = 1e-9;
int n;
double p;
double mem[26][26];

double solve(int a, int b) {
    if(a == n) {
        return 1;
    }
    if(b == n) {
        return 0;
    }
    if(mem[a][b] != -1) {
        return mem[a][b];
    }
    double &ret = mem[a][b];
    ret = p*solve(a+1,b) + (1-p)*solve(a,b+1);
    return ret;
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    cout.precision(2);
    cout << fixed;
    int t;
    cin >> t;
    while(t--) {
        for(int i = 0; i < 26; i++) {
            for(int j = 0; j < 26; j++) {
                mem[i][j] = -1;
            }
        }
        cin >> n >> p;
        cout << solve(0,0) << "\n";
    }

    return 0;
}