#include<atcoder/all>
#include<bits/stdc++.h>
using namespace atcoder;
using namespace std;
#define all(a) a.begin(),a.end()
#define rall(a) a.rbegin(),a.rend()
#define fin(...) return pt(__VA_ARGS__)
#define cont(...) pt(__VA_ARGS__);continue
#define eb(...) emplace_back(__VA_ARGS__)
#define ef(...) emplace_front(__VA_ARGS__)
#define elif(...) else if(__VA_ARGS__)
#define overload4(a,b,c,d,e,...) e
#define rep1(b) for(ll _i=0;_i<(ll)(b);_i++)
#define rep2(i,b) for(ll i=0;i<(ll)(b);i++)
#define rep3(i,a,b) for(ll i=(ll)(a);i<(ll)(b);i++)
#define rep4(i,a,b,c) for(ll i=(ll)(a);i<(ll)(b);i+=(ll)(c))
#define rep(...) overload4(__VA_ARGS__,rep4,rep3,rep2,rep1)(__VA_ARGS__)
#define rrep1(a) for(ll _i=(ll)(a);_i>=0;_i--)
#define rrep2(i,a) for(ll i=(ll)(a);i>=0;i--)
#define rrep3(i,a,b) for(ll i=(ll)(a);i>=(ll)(b);i--)
#define rrep4(i,a,b,c) for(ll i=(ll)(a);i>=(ll)(b);i-=(ll)(c))
#define rrep(...) overload4(__VA_ARGS__,rrep4,rrep3,rrep2,rrep1)(__VA_ARGS__)
#define LL(...) ll __VA_ARGS__;lin(__VA_ARGS__)
#define LD(...) ld __VA_ARGS__;lin(__VA_ARGS__)
using ll=long long;
using ld=long double;
using v1=vector<ll>;
using v2=vector<v1>;
using v3=vector<v2>;
using v4=vector<v3>;
using pll=pair<ll,ll>;
using mll=map<ll,ll>;
using mint=modint998244353;
ll inf=3e18;
ld pi=acos(-1);
ld eps=1e-10;
template<class T>v1&operator++(vector<T>&v){for(T&x:v)x++;return v;}
template<class T>v1&operator--(vector<T>&v){for(T&x:v)x--;return v;}
template<class T>v1 operator++(vector<T>&v,int){v1 r=v;++v;return r;}
template<class T>v1 operator--(vector<T>&v,int){v1 r=v;--v;return r;}
template<class T>using max_priority_queue=std::priority_queue<T>;
template<class T>using min_priority_queue=std::priority_queue<T,vector<T>,greater<T>>;
template<class T,class U>bool chmax(T&a,const U&b){return a<b?a=b,1:0;}
template<class T,class U>bool chmin(T&a,const U&b){return a>b?a=b,1:0;}
template<class T>T max(const vector<T>&a){return *max_element(all(a));}
template<class T>T min(const vector<T>&a){return *min_element(all(a));}
template<class...T>constexpr auto max(T...a){return max(initializer_list<common_type_t<T...>>{a...});}
template<class...T>constexpr auto min(T...a){return min(initializer_list<common_type_t<T...>>{a...});}
template<class T>T sum(const vector<T>&a){return accumulate(all(a),T(0));}
template<class T>T popcnt(T a){return __builtin_popcountll(a);}
template<class T>ll lbp(const vector<T>&a,const T&b){return lower_bound(all(a),b)-a.begin();}
template<class T>ll ubp(const vector<T>&a,const T&b){return upper_bound(all(a),b)-a.begin();}
template<class T>pll mima(const T&a,const T&b){return {min(a,b),max(a,b)};}
template<class T>void sort(vector<T>&v){sort(all(v));}
template<class T,class F>void sort(vector<T>&v,const F&f){sort(all(v),f);}
template<class T>void rev(vector<T>&v){reverse(all(v));}
template<class T>void uniq(vector<T>&v){sort(all(v));v.erase(unique(all(v)),v.end());}
void sort(string&s){sort(all(s));}
void rev(string&s){reverse(all(s));}
v1 iota(ll n,ll s=0){v1 a(n);iota(all(a),s);return a;}
void emplace_front(v1&v,ll x=0){v.emplace(v.begin(),x);}
//io
struct fast_ios{fast_ios(){cin.tie(nullptr);ios::sync_with_stdio(false);cout<<fixed<<setprecision(20);};}fast_ios_;
ostream&operator<<(ostream&os,const mint&x){return os<<x.val();}
template<class T,class U>istream&operator>>(istream&is,pair<T,U>&p){return is>>p.first>>p.second;}
template<class T,class U>ostream&operator<<(ostream&os,const pair<T,U>&p){return os<<p.first<<" "<<p.second;}
template<class T>istream&operator>>(istream&is,vector<T>&v){for(T&x:v)is>>x;return is;}
template<class T>ostream&operator<<(ostream&os,const vector<T>&v){rep(i,v.size())os<<v[i]<<(i+1==(ll)v.size()?"":" ");return os;}
template<class T>ostream&operator<<(ostream&os,const vector<vector<T>>&v){
  rep(i,v.size()){
    rep(j,v[i].size())os<<v[i][j]<<(j+1==(ll)v[i].size()?"":" ");
    if(i+1<(ll)v.size())cout<<'\n';
  }
  return os;
}
template<class T>ostream&operator<<(ostream&os,const set<T>&v){for(auto&x:v)os<<x<<(x==*v.rbegin()?"":" ");return os;}
template<class T,class U>ostream&operator<<(ostream&os,const map<T,U>&m){for(auto&[k,v]:m)os<<k<<" "<<v<<(k==(m.rbegin()->first)?"":"\n");return os;}
ll pt(){cout<<'\n';return 0;}
template<class T,class...A>ll pt(const T&a,const A&...b){cout<<a;((cout<<' '<<b),...);cout<<'\n';return 0;}
template<class...T>void vin(const ll k,vector<T>&...a){(cin>>...>>a[k]);}
template<class T,class...A>void vin(vector<T>&a,A&...b){rep(i,a.size())vin(i,a,b...);}
template<class T>void lin(T&a){cin>>a;}
template<class...T>void lin(T&...a){(cin>>...>>a);}
//other
template<class V,class T>void resize(vector<V>&v,const T&a){v.resize(a);}
template<class V,class T,class...A>void resize(vector<V>&vv,const T&a,const A&...b){vv.resize(a);for(V&v:vv)resize(v,b...);}
template<class V,class T>void fill(V&v,const T&x){v=x;}
template<class V,class T>void fill(vector<V>&vv,const T&x){for(V&v:vv)fill(v,x);}
void com(v1&v,v1&h){for(ll&x:h)x=lbp(v,x);}
template<class...T>void com(v1&v,v1&h,T&...t){for(ll&x:h)x=lbp(v,x);com(v,t...);}
template<class...T>v1 compress(T&...a){v1 v;for(auto&e:{a...})copy(all(e),back_inserter(v));uniq(v);com(v,a...);return v;}
template<class T>T binsearch(function<bool(T)>judge,T ok,T ng){
  T D=(*typeid(ok).name()=='x'?1:eps);
  while(abs(ok-ng)>D){
    T m=(ok+ng)/2;
    (judge(m)?ok:ng)=m;
  }
  return ok;
}
v1 divisor(ll n){mll m;for(ll i=1;i*i<=n;i++){if(n%i==0){m[i]++;m[n/i]++;}}v1 v;for(auto[x,_]:m)v.eb(x);return v;}
mll factor(ll n){mll m;for(ll i=2;i*i<=n;i++){while(n%i==0){m[i]++;n/=i;}}if(n>1)m[n]++;return m;}
ll mpow(ll x,ll n,ll m=0){ll r=1;while(n>0){if(n&1){r*=x;if(m)r%=m;}x*=x;if(m)x%=m;n>>=1;}return r;}
ll minv(ll a,ll m){ll b=m,u=1,v=0;while(b){ll t=a/b;a-=t*b;swap(a,b);u-=t*v;swap(u,v);}u%=m;if(u<0)u+=m;return u;}
ll lsqrt(ll x){ll r=sqrt(x)-1;while(r+1<=x/(r+1))r++;return r;}
ll llog2(ll n){ll r=0;while(n){n>>=1;r++;}return r;}
ll bit(ll n){return 1LL<<n;}
v1 dx={-1,0,1,0,-1,1,1,-1};
v1 dy={0,-1,0,1,-1,-1,1,1};
using S=ll;
S op(S a,S b){return a+b;}
S e(){return 0;}

int main(){
  LL(_);
  rep(_){
    LD(_T,_M,_L);
    ll T=100*_T,M=100*_M,L=100*_L;
    
    auto judge=[&](ll v){
      return 18*v*T*M+25*v*v<=6480*M*L;
    };
    
    ll ok=binsearch<ll>(judge,0,510001);
    cout<<ok/100<<'.';
    string s=to_string(ok%100);
    while(s.size()<2)s='0'+s;
    pt(s);
  }
}