#include <bits/stdc++.h>
using namespace std;
int32_t main() {
  ios::sync_with_stdio(false);
  cout.tie(0);
  cin.tie(0);
  long long t;
  cin >> t;
  while (t--) {
    long long n, m, k;
    cin >> n >> m >> k;
    long long cnt = n / k;
    if (m <= cnt)
      cout << m << '\n';
    else {
      long long cntt = (m - cnt + k - 2) / (k - 1);
      cout << (cnt - cntt) << '\n';
    }
  }
  return 0;
}
