#include #include #include #include #include #include #include #include #include #include #include using namespace std; typedef long long ll; int main() { int N; cin >> N; for (int i = 0; i < N; ++i) { double T, u, L; cin >> T >> u >> L; double ok = 0.0; double ng = 5200; for (int i = 0; i < 200; ++i) { double v = (ok + ng) / 2.0; double l = 20 * u * v * T + (v * v); if (l <= L * 20 * u) { ok = v; } else { ng = v; } } double ans = 3600 * ok / 1000; cout << fixed << setprecision(2) << floor(100 * ans) / 100 << endl; } return 0; }