#include<iostream>
#include<cstdio>
#include<queue>
#include<algorithm>
#include<vector>
#include<cstring>
#include<string>
#include<map>
#include<stack>
#include<cmath>
#include<set>
#include<climits>
#include<iomanip>
#include<cassert>
using namespace std;
typedef long long LL;
typedef long double LB;
#define N 101
#define mod 1000000007
#define PI acos(-1)
const int INF=INT_MAX;
int main()
{
    int t;
    LL n,k,d,sum,a,b,x;
    scanf("%d",&t);
    while(t--)
    {
        scanf("%I64d%I64d",&n,&k);

        if((1+k)*k/2>n) {printf("-1\n");continue;}

        sum=(1+k)*k/2;
        d=n-sum;
        a=d/k;
        b=d%k;


        LL ans=1;
        for(int i=1;i<=k;i++)
        {
            if(i<=k-b) ans=(ans*(i+a))%mod;
            else ans=(ans*(i+a+1))%mod;
        }
        printf("%I64d\n",ans);

    }
    return 0;
}