/**
 * Mar 19, 2016 7:43:41 PM
 * PrjName: Bc76-02
 * @semprathlon
 */
import java.io.*;
import java.util.*;
public class Main {
    final static long mod=1000000007L;
    static int cal(long x,long n,long k){
        return ((x+x+k-1L)*k>>1)>n?1:0;
    }
    static int bisearch(int n,long k){
        int l=1,r=n;
        while(l<r){
            int m=(l+r+1)>>1;
            if (cal(m,n,k)>0)
                r=m-1;
            else
                l=m;
        }
        return l;
    }
    static long solve(int n,int k){
        if (((1L+k)*(long)k>>1)>(long)n)
            return -1;
        int tmp=bisearch(n, k);
        long res=1L;
        int sum=(tmp+tmp+k-1)*k>>1;
        for(int i=tmp;i<tmp+k;i++){
            if (tmp+k-i<=n-sum)
                res*=(long)(i+1);
            else
                res*=(long)i;
            res%=mod;
        }
        return res;
    }
    public static void main(String[] args) throws IOException{
        InputReader in=new InputReader(System.in);
        PrintWriter out=new PrintWriter(System.out);
        int T=in.nextInt();
        while(T-->0){
            int n=in.nextInt();
            int k=in.nextInt();
            out.println(solve(n, k));
        }
        out.flush();
        out.close();
    }

}
class InputReader {
    public BufferedReader reader;
    public StringTokenizer tokenizer;

    public InputReader(InputStream stream) {
        reader = new BufferedReader(new InputStreamReader(stream), 32768);
        tokenizer = null;
    }

    public String nextLine() {
        String tmp = null;
        try {
            tmp = reader.readLine();
            tokenizer = new StringTokenizer(tmp);
        } catch (IOException e) {
            throw new RuntimeException(e);
        } catch (NullPointerException e) {
            return null;
        }
        return tmp;
    }

    public String next() {
        while (tokenizer == null || !tokenizer.hasMoreTokens()) {
            try {
                tokenizer = new StringTokenizer(reader.readLine());
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        }
        return tokenizer.nextToken();
    }

    public int nextInt() {
        return Integer.parseInt(next());
    }

    public long nextLong() {
        return Long.parseLong(next());
    }

    public double nextDouble() {
        return Double.parseDouble(next());
    }
}