#include <bits/stdc++.h>
using namespace std;
typedef signed long long ll;

#define _P(...) (void)printf(__VA_ARGS__)
#define FOR(x,to) for(x=0;x<(to);x++)
#define FORR(x,arr) for(auto& x:arr)
#define FORR2(x,y,arr) for(auto& [x,y]:arr)
#define ALL(a) (a.begin()),(a.end())
#define ZERO(a) memset(a,0,sizeof(a))
#define MINUS(a) memset(a,0xff,sizeof(a))
template<class T> bool chmax(T &a, const T &b) { if(a<b){a=b;return 1;}return 0;}
template<class T> bool chmin(T &a, const T &b) { if(a>b){a=b;return 1;}return 0;}
//-------------------------------------------------------


int N;
double T,U,L;

ll hoge(ll v,ll T,ll m,ll L) {
	ll a=10*v*T*m*36;
	ll b=10*10*v*v*5;
	ll c=100*36*36*L*m;
	return a+b<=c;
}

void solve() {
	int i,j,k,l,r,x,y; string s;
	
	cin>>N;
	while(N--) {
		cin>>T>>U>>L;
		T=T*100+0.1;
		U=U*100+0.1;
		L=L*100+0.1;
		int ma=0;
		for(i=20;i>=0;i--) if(hoge(ma+(1<<i),T,U,L)) ma+=1<<i;
		
		_P("%.2lf\n",ma/100.0);
	}
}


int main(int argc,char** argv){
	string s;int i;
	if(argc==1) ios::sync_with_stdio(false), cin.tie(0);
	FOR(i,argc-1) s+=argv[i+1],s+='\n'; FOR(i,s.size()) ungetc(s[s.size()-1-i],stdin);
	cout.tie(0); solve(); return 0;
}