#include <iostream>
#include <stack>
#include <set>
#include <vector>
#include <list>
using namespace std;
double dm(int k)
{
double ans = 1;
for (int i = 1; i <= k + 1; i++)
{
ans = ans * i;
}
return ans;
}
double ds(int k, int n)
{
double ans = 1;
for (int i = 0; i <= k; i++)
{
ans = ans * (n + i);
}
return ans;
}
int main()
{
cin.tie(NULL);
cout.tie(NULL);
ios::sync_with_stdio(false);
int t;
cin >> t;
int k, n;
double ss,mm;
for (int i = 0; i < t; i++)
{
cin >> k;
cin >> n;
ss = ds(k, n);
mm = dm(k);
cout << ss / mm<<'\n';
}
}
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