#include <cstdio>
#include <cstring> 
#include <iostream>

using namespace std;
const int N = 1e6;
typedef long long llg;
const llg oo = 1e9+7;

int main()
{
    int cas;
    scanf("%d",&cas);
    while(cas--)
    {
        llg x,n;
        cin>>x>>n;
        if(n>x || x < (n+1LL)*n/2 ) cout<<"-1"<<endl;
        else
        {
            llg y = x - (n+1LL)*n/2;
            llg z = y / n;
            llg p = y % n;
            llg tmp = z,ans = 1;
            for(llg i=1;i<=n;i++)
            {
                if(n-p+1 == i) tmp++;
                tmp++;
                ans = (ans * tmp) % oo;
            }
            cout<<ans<<endl;
        }
    }
    return 0;
}