#include<bits/stdc++.h>
using namespace std;
#define rep(i,n) for(ll i=0;i<n;i++)
#define repl(i,l,r) for(ll i=(l);i<(r);i++)
#define per(i,n) for(ll i=(n)-1;i>=0;i--)
#define perl(i,r,l) for(ll i=r-1;i>=l;i--)
#define fi first
#define se second
#define pb push_back
#define ins insert
#define pqueue(x) priority_queue<x,vector<x>,greater<x>>
#define all(x) (x).begin(),(x).end()
#define CST(x) cout<<fixed<<setprecision(x)
#define vtpl(x,y,z) vector<tuple<x,y,z>>
#define rev(x) reverse(x);
using ll=long long;
using vl=vector<ll>;
using vvl=vector<vector<ll>>;
using pl=pair<ll,ll>;
using vpl=vector<pl>;
using vvpl=vector<vpl>;
const ll MOD=1000000007;
const ll MOD9=998244353;
const int inf=1e9+10;
const ll INF=4e18;
const ll dy[9]={0,1,-1,0,1,1,-1,-1,0};
const ll dx[9]={1,0,0,-1,1,-1,1,-1,0};
template<class T> inline bool chmin(T& a, T b) {
    if (a > b) {
        a = b;
        return true;
    }
    return false;
}
template<class T> inline bool chmax(T& a, T b) {
    if (a < b) {
        a = b;
        return true;
    }
    return false;
}

int main(){
    ll m;cin >> m;
    using ld=long double;
    CST(11);
    while(m--){
        ll a,b;cin >> a >> b;
        ld t;cin >> t;
        auto fx=[&](ld x)->ld{
            return pow(x,a)*pow(log(x),b)-t;
        };
        auto dfx=[&](ld x)->ld{
            if(a>0&&b>0){
                return pow(x,a-1)*pow(log(x),b-1)*(log(x)*a+b);
            }
            else if(a==0){
                return pow(log(x),b-1)*b/x;
            }
            else {
                return pow(x,a-1)*a;
            }
        };
        ld ans=1;
        rep(_,10){
            ans=ans-fx(ans)/dfx(ans);
        }
        cout << ans << endl;
    }
}