//shared共享
//Nc the number of distinct common numbers shared by the two sets
//Nt is the total number of distinct numbers in the two sets. Your job is to calculate the 
//Nc是两个集合中都存在的不同整数的数量，Nt是两个集合中不同整数的数量。

#include <iostream>
#include <cstring>
#include <algorithm>
#include <unordered_set>

using namespace std;

const int N = 60;
unordered_set<int> S[N];

int main()
{
    int n;
    cin>>n;
    for (int i = 1; i <= n; i ++ )
    {
        int cnt;
        cin>>cnt;
        while(cnt--)
        {
            int x;
            cin>>x;
            S[i].insert(x);
        }
    }
    int k;
    cin>>k;
    while(k--)
    {
        int a,b;
        cin>>a>>b;
        int res = 0,sa=0;
        for(auto k :S[a])
            if(S[b].count(k)) sa++;
        res  = S[a].size()+S[b].size()-sa;
        printf("%.1lf%%\n",(double)sa/res*100);
    }
    return 0;
}