#include <bits/stdc++.h>
using namespace std;
int main() {
  int t;
  cin >> t;
  while (t--) {
    long long n, x;
    cin >> n >> x;
    long long a[n];
    for (long long i = 0; i < n; i++) cin >> a[i];
    sort(a, a + n, greater<long long>());
    long long sum = 0, c = n;
    for (long long i = 0; i < n; i++) {
      sum += a[i];
      if (sum < x * (i + 1)) {
        c = i;
        break;
      }
    }
    cout << c << endl;
  }
  return 0;
}
