//まさか
#include <bits/stdc++.h>
using namespace std;
const double eps = 0.000000001;
int main(){
  int N;
  cin >> N;
  for (int i = 0; i < N; i++){
    double T, m, L;
    cin >> T >> m >> L;
    double tv = 0, fv = 5100;
    for (int j = 0; j < 100; j++){
      double mid = (tv + fv) / 2;
      if (mid * T + mid * mid / (20 * m) <= L){
        tv = mid;
      } else {
        fv = mid;
      }
    }
    int ans = tv * 360 + eps;
    string ans2 = to_string(ans);
    while (ans2.size() < 3){
      ans2.insert(ans2.begin(), '0');
    }
    ans2.insert(ans2.end() - 2, '.');
    cout << ans2 << endl;
  }
}