#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(){
    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 = 18360000;
    ll mid;
    while(hi - lo > 1){
        mid = (lo + hi)/2;
        if(100LL*mid*mid+72LL*nu*nt*mid > 20LL*36LL*36LL*nu*nl) 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);
}