// {{{ Templates
#include <bits/stdc++.h>

#define show(x) cerr << #x << " = " << x << endl

using namespace std;
using ll = long long;
using pii = pair<int, int>;
using vi = vector<int>;

template <typename T>
ostream& operator<<(ostream& os, const vector<T>& v)
{
    os << "sz:" << v.size() << "\n[";
    for (const auto& p : v) {
        os << p << ",";
    }
    os << "]\n";
    return os;
}

template <typename S, typename T>
ostream& operator<<(ostream& os, const pair<S, T>& p)
{
    os << "(" << p.first << "," << p.second
       << ")";
    return os;
}


constexpr ll MOD = (ll)1e9 + 7LL;

template <typename T>
constexpr T INF = numeric_limits<T>::max() / 100;

// }}}

inline long double binlarge(const ll a, const ll b, const long double t)
{
    const long double lgt = log(t);
    long double inf = 0.0;
    long double sup = exp(t) + 0.01;
    for (int i = 0; i < 40; i++) {
        const long double mid = (inf + sup) / 2;
        const long double c = a * mid + b * log(mid);
        if (c < lgt) {
            inf = mid;
        } else {
            sup = mid;
        }
    }
    return exp(inf);
}

inline long double small(const ll a, const long double t)
{
    const long double inf = log(t) / a;
    return exp(inf);
}

int main()
{
    cin.tie(0);
    ios::sync_with_stdio(false);
    ll m;
    cin >> m;
    for (ll i = 0; i < m; i++) {
        ll a, b;
        cin >> a >> b;
        long double t;
        cin >> t;
        if (b == 0 and t < 1.0) {
            cout << fixed << setprecision(12) << small(a, t) << "\n";
        } else {
            cout << fixed << setprecision(12) << binlarge(a, b, t) << "\n";
        }
    }
    return 0;
}