#include <cstdio>
#include <cassert>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <iostream>
#include <algorithm>
#include <vector>
#include <map>
#include <set>
#include <cctype>
#include <utility>
#include <queue>
#include <cmath>
#include <complex>
using namespace std;

typedef long long LL;
typedef pair<int, int> PII;
typedef vector<int> VI;
typedef vector<PII> VPII;
typedef pair<LL, LL> PLL;
typedef pair<int, LL> PIL;
typedef pair<LL, int> PLI;
typedef double DB;

#define pb push_back
#define mset(a, b) memset(a, b, sizeof a)
#define all(x) (x).begin(), (x).end()
#define bit(x) (1 << (x))
#define bitl(x) (1LL << (x))
#define sqr(x) ((x) * (x))
#define sz(x) ((int)(x.size()))
#define cnti(x) (__builtin_popcount(x))
#define cntl(x) (__builtin_popcountll(x))
#define clzi(x) (__builtin_clz(x))
#define clzl(x) (__builtin_clzll(x))
#define ctzi(x) (__builtin_ctz(x))
#define ctzl(x) (__builtin_ctzll(x))

#define X first
#define Y second

#define Error(x) cout << #x << " = " << x << endl

template <typename T, typename U> 
inline void chkmax(T& x, U y) {
    if (x < y) x = y;
}

template <typename T, typename U>
inline void chkmin(T& x, U y) {
    if (y < x) x = y;
}

const int MOD = 1e9 + 7;
int A[1000005];

int modExp(int a, int b, int m) {
    int rlt = 1;
    for (; b; b /= 2, a = (LL)a * a % m) 
        if (b & 1) rlt = (LL)rlt * a % m;
    return rlt;
}

int main() {
    
    int tn;
    for (cin >> tn; tn--; ) {
        int n, K;
        scanf("%d%d", &n, &K);
        if (n < (LL)K * (K + 1) / 2) {
            puts("-1");
            continue;
        }
        
        n -= (LL)K * (K + 1) / 2;
        int a = n / K;
        int m = n % K;
        for (int i = 0; i < K; i++) {
            if (i < K - m) A[i] = a;
            else A[i] = a + 1;
        }
        int ans = 1;
        for (int i = 0; i < K; i++) A[i] += i + 1, ans = (LL)ans * A[i] % MOD;
        printf("%d\n", ans);
    
    }
    
    return 0;
}