#include<bits/stdc++.h>
#define rep(i,j,k) for (int i=j;i<(k);++i)
using namespace std;

typedef vector<float> vd;

int main() {
    int n;
    cin >> n;

    vector<int> counts(n);
    unordered_map<string, int> mapper;
    float total = 0;
    rep(i,0,n) {
        string w;
        cin >> counts[i] >> w;
        mapper[w] = i;
        total += counts[i];
    }

    vector<vd> dp(n, vd(n));

    if (n==1) {
        dp[0][0] = 1;
    } else if (n==2) {
        float a0 = counts[0] / total;

        dp[0][0] = a0;
        dp[1][0] = 1-a0;
        dp[0][1] = dp[1][1] = 1;
    } else {

        rep(i,0,n) {
            rep(j,i+1,n) {
                rep(k,j+1,n) {
                    float sub = counts[i] * counts[j] * counts[k];
                    float ijk = 1 / total / (total - counts[i]) / (total - counts[i] - counts[j]);
                    float ikj = 1 / total / (total - counts[i]) / (total - counts[i] - counts[k]);

                    float jik = 1 / total / (total - counts[j]) / (total - counts[j] - counts[i]);
                    float jki = 1 / total / (total - counts[j]) / (total - counts[j] - counts[k]);

                    float kij = 1 / total / (total - counts[k]) / (total - counts[k] - counts[i]);
                    float kji = 1 / total / (total - counts[k]) / (total - counts[k] - counts[j]);

                    dp[i][0] += sub*(ijk + ikj);
                    dp[i][1] += sub*(jik + kij);
                    dp[i][2] += sub*(jki + kji);

                    dp[j][0] += sub*(jik + jki);
                    dp[j][1] += sub*(ijk + kji);
                    dp[j][2] += sub*(ikj + kij);

                    dp[k][0] += sub*(kij + kji);
                    dp[k][1] += sub*(ikj + jki);
                    dp[k][2] += sub*(ijk + jik);

                    float comb = sub*(ijk + ikj + jik + jki + kij + kji);

                    int ind=2;

                    rep(x,0,n) if (x!=i && x!=j && x!=k) dp[x][++ind] += comb;
                }
            }
        }

        // prefix sum i is in top j
        rep(i,0,n) rep(j,1,n) {
            dp[i][j] += dp[i][j-1];
        }
    }


    // queries
    int q;
    cin >> q;

    while (q--) {
        string w;
        int p;
        cin >> w >> p;
        printf("%.12f\n", dp[mapper[w]][--p]);
    }

    return 0;
}