#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)
#define all(a) (a).begin(), (a).end()
#define pb push_back
#define fi first
#define se second

const ll MOD = 1000000007;
const ll MOD2 = 998244353;
const ll INF = 1LL << 60;
const ll N_MAX = 2e5;

ll solve(){
    double t, u, l;
    cin >> t >> u >> l;

    ll nt = (ll)((double)100*t);
    ll nu = (ll)((double)100*u);
    ll nl = (ll)((double)100*l);

    ll lo = 0;
    ll hi = 1000000000;
    ll mid;
    while(hi - lo > 1){
        mid = (lo + hi)/2;
        if(100*mid*mid+720*nu*nt*mid-2592000*nu*nl > 0) hi = mid;
        else lo = mid;
    }
    
    return lo/10;
}

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

    vector<ll> ans(n);
    rep(i, n) ans[i] = solve();
    rep(i, n) cout << fixed << setprecision(2) << (double)ans[i]/(double)100 << endl;
}