#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);

        ll w = 20 * u;
        ll Tw36000 = T * w * 36000;
        ll magic = 3600 * 3600;
        ll Lw = L * w;
        ll left = Lw * magic;
        for(ll V = 600100;V >= 0;V--){
            if(left >= V * Tw36000 + V * V * 1000000){
                printf("%lld.%02lld\n", V / 100, V % 100);
                break; 
            }
        }
    }
    return 0;
}