#include <bits/stdc++.h>
using namespace std;

#define ll long long int
#define ull unsigned long long int
#define uint unsigned int

typedef pair<int,int> pii;
#define x first
#define y second

#define read(n) scanf("%d",&n)
#define readll(n) scanf("%lld",&n)
#define read2(n,m) scanf("%d%d",&n,&m)
#define read3(n,m,l) scanf("%d%d%d",&n,&m,&l)

#define fr(i,n)     for(int i=0;i<n;i++)
#define frr(i,a,b)   for(int i=a;i<b;i++)
#define rf(i,n)     for(int i=n-1;i>=0;i--)

#define init(mem,v) memset(mem,v,sizeof(mem))

#define DB(x)              cout<<__LINE__<<" :: "<<#x<< ": "<<x<<endl;
#define DB2(x, y)          cout<<__LINE__<<" :: "<<#x<< ": "<<x<<" | "<<#y<< ": "<<y<<endl;
#define DB3(x, y, z)       cout<<__LINE__<<" :: "<<#x<< ": "<<x<<" | "<<#y<< ": "<<y<<" | "<<#z<<": "<<z<<endl;
#define DB4(a, b, c, d)    cout<<__LINE__<<" :: "<<#a<< ": "<<a<<" | "<<#b<< ": "<<b<<" | "<<#c<<": "<<c<<" | "<<#d<<": "<<d<<endl;

#define md 1000000007

// a^b mod md
ll ppow(ll a,ll b){
    ll rem=1;
    while(b){
        if(b%2 == 0){
            b/=2;
            a=(a*a)%md;
        }
        else{
            b--;
            rem=(rem*a)%md;
        }
    }
    return rem;
}

ll solve_small(ll M,ll R){
    ll val=0;
    ll tmp=M;
    for(int i=1;i<=R-1;i++){
        val=(val+tmp)%md;
        tmp=(tmp*M)%md;
    }
    val=(val+md-(R-1)%md)%md;
    assert(val>=0 and val<md);
    return val;
}

ll solve_large(ll M,ll R){
    ll ans=(ppow(M,R-1)+md-1)%md;
    ans=(ans*M)%md;
    ans=ans*(ppow(M-1,md-2))%md;
    ans=(ans+md-(R-1)%md)%md;
    assert(ans>=0 and ans<md);
    return ans;
}

int main(){
    int t;
    ll M,R;
    read(t);
    while(t--){
        scanf("%lld%lld",&M,&R);
        printf("%lld\n",solve_large(M,R));
    }
}