#include <bits/stdc++.h>
using namespace std;
using lld = signed long long int;
lld solve() {
  lld n, m, k;
  cin >> n >> m >> k;
  lld x = n / k;
  if (m <= x) return m;
  if (m <= x + (k - 1)) return x - 1;
  return x - ceil((m - x) / (k - 1.0));
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  int t;
  cin >> t;
  while (t--) {
    cout << solve() << "\n";
  }
  return 0;
}
