#include <algorithm>
#include <cstdio>
#include <cstdlib>
#include <cctype>
#include <cmath>
#include <iostream>
#include <queue>
#include <list>
#include <stack>
#include <map>
#include <numeric>
#include <set>
#include <sstream>
#include <string>
#include <vector>
using namespace std;
#define REP(i,a,n) for(int i=(a); i<(int)(n); i++)
#define rep(i,n) REP(i,0,n)
#define FOR(it,c) for(__typeof((c).begin()) it=(c).begin(); it!=(c).end(); ++it)
#define ALLOF(c) (c).begin(), (c).end()
typedef long long ll;

int main(){
  int m;
  cin >> m;
  rep(i,m){
    int a, b;
    double t;
    cin >> a >> b >> t;

    double x = 1.0;
    double logt = log(t);
    rep(j,15){
      double delta = (a * x + b * log(x) - logt) / (a + b / x);
      x = x - delta;
    }
    printf("%.12lf\n", exp(x));
  }
  
  return 0;
}