#include<bits/stdc++.h>

using namespace std;
using ll = long long;

int main(){
    int N;cin >> N;
    while(N--){
        string _T, _u, _L;
        cin >> _T >> _u >> _L;
        _T.erase(find(_T.begin(), _T.end(), '.'));
        _u.erase(find(_u.begin(), _u.end(), '.'));
        _L.erase(find(_L.begin(), _L.end(), '.'));

        ll T = stoi(_T);
        ll u = stoi(_u);
        ll L = stoi(_L);
        
        for(ll V = 600100;V >= 0;V--){
            if(L * (20 * u) * (3600 * 3600) >= V * 3600 * T * (20 * u) * 10 + V * V * (1000000)){
                printf("%lld.%02lld\n", V / 100, V % 100);
                break; 
            }
        }
    }
    return 0;
}