#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cstdlib>
#include <cstring>
#include <string.h>
#include <string>
#include <map>
#include <queue>
#include <deque>
#include <cmath>
#include <math.h>
#include <vector>
#include <ctime>
#include <cctype>
#include <stack>
#include <set>
#include <bitset>
#include <functional>
#include <numeric>
#include <stdexcept>
#include <utility>
using namespace std;
#define ll long long 
#define m0(a) memset(a, 0, sizeof(a))
#define m1(a) memset(a, -1, sizeof(a))
#define C1(x)  cout<<x<<endl;
#define C2(x,y)  cout<<x<<" "<<y<<endl;
#define C3(x,y,z)  cout<<x<<" "<<y<<" "<<z<<endl;

const int inf = 0x3f3f3f3f; 
const double eps = 1e-15;
const double pi = acos((double)-1) ;
const int maxn = 100100;
const ll M = 1e9+7;
ll i,j,k,l,m,n,x,y,z,ans,num;
int a[maxn]={0};
int v[maxn]={0};
int dx[4]={0,0,1,-1};
int dy[4]={1,-1,0,0};
int main()
{
    #ifdef ONLINE_JUDGE

    #else

        //freopen("in.txt","r",stdin);

    #endif
    int cas;
    scanf("%d",&cas);
    for (int casi=1;casi<=cas;casi++)
    {
        scanf("%I64d%I64d",&n,&k);
        double xx;
        xx=sqrt(2*(double)n+0.25)-0.5;
        l=(ll)(xx+1e-9);
        if (k>l)
        {
            printf("-1\n");
            continue;
        }
        ll ans=1;

        ll x,y,z;
        
        x=(n-(((k)*(k+1))/2))/(k);
        y=(n-(((k)*(k+1))/2))-x*k;
        
        //printf("%I64d  %I64d \n",x,y);
        
        for (ll i=1;i<=k-y;i++)
        {
            //printf("!@#%I64d\n",x);
            ans=(ans*(i+x)) % M;
            //printf("%I64d  %I64d  %I64d\n",i,x,ans);
        }
        
        for (ll i=k-y+1;i<=k;i++)
        {
            //printf("!@#%I64d\n",x);
            ans=(ans*(i+x+1)) % M;
            //printf("%I64d  %I64d  %I64d\n",i,x,ans);
        }
        printf("%I64d\n",ans);
        
    }
    return 0;
}