#include <bits/stdc++.h>
using namespace std;

using D = long double;
const D EPS = 1e-10;

D f(D T, D mu, D L) {
    D V = 3.6 * (sqrt(100 * mu * mu * T * T + 20 * mu * L) - 10.0 * mu * T);
    if (abs(V) < EPS) V = 0;
    return V;
}

int main() {
    int N;
    cin >> N;
    for (int i = 0; i < N; ++i) {
        D T, mu, L;
        cin >> T >> mu >> L;
        cout << fixed << setprecision(2) << (int)(f(T, mu, L) * 100) / 100.0 << endl;
    }
}