#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pll = pair<ll, ll>;
#define drep(i, cc, n) for (ll i = (cc); i <= (n); ++i)
#define rep(i, n) drep(i, 0, n - 1)

ll solve(){
    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 lo = 0;
    ll hi = 18360000;
    ll mid;
    while(hi - lo > 1){
        mid = (lo + hi)/2;
        if(100LL*mid*mid+72LL*u*t*mid > 20LL*36LL*36LL*u*l) hi = mid;
        else lo = mid;
    }
    
    return lo;
}

int main(){
    ll n;
    cin >> n;

    vector<ll> ans(n);
    rep(i, n) ans[i] = solve();
    rep(i, n) printf("%lld.%02lld\n", ans[i]/100, ans[i]%100);
}