#include <bits/stdc++.h>
using namespace std;

static inline void solve() {

  int T;
  cin >> T;

  for (int testcase = 1; testcase <= T; testcase++) {
    double t, m, l;
    cin >> t >> m >> l;
    double left = 0, right = 5100.0 * 1000.0 / 3600.0;
    for (int it = 0; it < 100; it++) {
      double mid = (left + right) * 0.5;
      double len = mid * t + mid * mid / (20 * m);
      if (len <= l) {
        left = mid;
      } else {
        right = mid;
      }
    }
    double ans = (left + right) * 0.5;
    long long lans = ans * 3600.0 * 0.1;
    ans = (double)lans * 0.01;
    printf("%.2lf\n", ans);
  }
}

int main() {
  ios_base::sync_with_stdio(0), cin.tie(0);
#ifdef LOCAL
  int T;
  cin >> T;
  for (int tc = 1; tc <= T; tc++) {
    cout << "Case" << tc << ":" << '\n';
    solve();
  }
#else
  solve();
#endif
  return 0;
}