#include <stdio.h>
#include <atcoder/all>
#include <bits/stdc++.h>
using namespace std;
using namespace atcoder;
using mint = modint998244353;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf 1000000001



int main(){
	
	int _t;
	cin>>_t;
	
	rep(_,_t){
		long long T,m,L;
		{
			double tt,mm,LL;
			cin>>tt>>mm>>LL;
			T = round(tt*100.0);
			m = round(mm*100.0);
			L = round(LL*100.0);
		}
		L *= 100;
		long long ok = 0,ng = 5100 * 100+1;
		
		while(ng-ok>1LL){
			long long mid  =(ok+ng)/2;
			long long V = mid;
			if(m*L*18*18 >= V*T*m*18*5 + V*V*5*5*5)ok = mid;
			else ng = mid;
			
		}
		double ans = ok;
		ans /= 100.0;
		cout<<fixed<<setprecision(2)<<ans<<endl;
		
		
	}
	
    return 0;
}