#include <bits/stdc++.h>
using namespace std;
const int MOD = 1e9 + 7;
long long qpow(long long base, long long exp, long long mod) {
long long res = 1;
base %= mod;
while (exp > 0) {
if (exp & 1)
res = (res * base) % mod;
base = (base * base) % mod;
exp >>= 1;
}
return res;
}
int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
int t;
cin >> t;
while (t--) {
long long n, k;
cin >> n >> k;
long long ans = 0;
long long power = 1;
while (k > 0){
if (k & 1)
ans = (ans + power) % MOD;
power = (power * n) % MOD;
k >>= 1;
}
cout << ans << '\n';
}
return 0;
}
