#include <iostream>

 #include <cstdio>

 #include <algorithm>

 #include <cstring>

 #include <set>

 using namespace std;

 const int maxn = ;

 set<int> gather[maxn];

 int main()

 {

     int n = ,m = ;

     scanf("%d",&n);

     for(int i=;i<=n;i++)

     {

         scanf("%d",&m);

         for(int j=;j<m;j++)

         {

             int x;

             scanf("%d",&x);

             gather[i].insert(x);

         }

     }

     int k = ;

     scanf("%d",&k);

     int l = ,r = ;

     while(k--)

     {

         scanf("%d %d",&l,&r);

         int Count = ;

         set<int>::iterator it;

         for(it=gather[l].begin();it!=gather[l].end();it++)

         {

             if(gather[r].count(*(it)))

             {

                 Count++;

             }

            // printf("%d\n",*it);

         }

         printf("%.2f%%\n",(double)Count/(double)(gather[l].size()+gather[r].size()-Count)*100.0);

     }

     return ;

 }