#include<cstdio>
#include<cstring>
#include<algorithm>
#include<cstdlib>
#include<cmath>
#include<vector>
#include<queue>
#include<map>
#include<set>
using namespace std;
int a[105];
__int64 ans,mod=1e9+7;
int main(){
    int i,j,n,m,T,k,t,sum,vmax;
    scanf("%d",&T);
    while(T--){
        scanf("%d%d",&n,&k);
        if(1LL*(k)*(k+1)/2>1LL*n){
            printf("-1\n");
            continue;
        }
        sum=(1+k)*k/2;
        vmax=k;
        while(sum<n){
            sum+=vmax+1;
            sum-=vmax-k+1;
            vmax++;
        }
        ans=1;
        if(sum==n){
            for(i=1;i<=k;i++){
                ans*=vmax;
                ans%=mod;
                vmax--;
            }
        }
        else{
            t=sum-n;
            vmax-=k;
            vmax++;
            for(i=1;i<=k;i++){
                if(i==t){
                    ans*=(vmax-t);
                    ans%=mod;
                    vmax++;
                }
                else{
                    ans*=vmax;
                    ans%=mod;
                    vmax++;
                }
            }
        }
        printf("%I64d\n",ans);
    }
    //system("pause");
    return 0;
}