import java.util.*;

public class draftlottery_ls {
    static double[][] dp;
    static int[] counts;
    static int n;

    static void solve(int s, int p, int total, double cur, boolean[] selected) {
        if (s == 0) {
            for (int i=0; i<n; ++i) if (!selected[i]) {
                dp[i][p++] += cur;
            }
        } else {
            for (int i=0; i<n; ++i) if (!selected[i]) {
                selected[i] = true;

                double scur = cur * counts[i] / total;

                dp[i][p] += scur;
                solve(s-1, p+1, total-counts[i], scur, selected);

                selected[i] = false;
            }
        }
    }

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);

        n = in.nextInt();

        counts = new int[n];
        HashMap<String, Integer> mapper = new HashMap<>();

        int total = 0;
        for (int i=0;i<n;++i) {
            int x = in.nextInt();
            String w = in.next();

            total += counts[i] = x;
            mapper.put(w, i);

        }

        dp = new double[n][n];

        solve(3, 0, total, 1.0, new boolean[n]);

        for (int i=0;i<n;++i) for (int j=1;j<n;++j) dp[i][j] += dp[i][j-1];

        // answer queries
        int q = in.nextInt();

        while (q --> 0) {
            String w = in.next();
            int k = in.nextInt();

            System.out.println(dp[mapper.get(w)][k-1]);
        }
    }
}