#include <bits/stdc++.h>
using namespace std;
#define M 1000000007
#define mp make_pair
#define pb push_back
#define tri pair<int, pair<int, int> >
#define TRI(a,b,c) (make_pair(a,make_pair(b,c)))
typedef long long ll;
typedef long double ld;
ll powmod(ll x, ll y)
{
if(y==0) return 1;
ll ret = powmod(x, y/2);
if(y%2==0) return (ret*ret)%M;
else return (((ret*ret)%M)*x)%M;
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
int t; cin>>t;
for(int t0=0; t0<t; t0++)
{
ll m, k; cin>>m>>k;
ll ans = 0, curr = 1;
for(int i=0; i<k; i++)
{
ans = (ans+curr)%M;
curr = (curr*m)%M;
}
if(k>1)ans = (ans+(k-2)/(m-1)+1)%M;
cout<<ans<<endl;
}
return 0;
}
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