#include <iostream>
#include <vector>
#include <queue>
using namespace std;

struct contract {
  unsigned a, b, d; // coefficient of a contract
  unsigned t; // job time worked
  
  contract(unsigned a, unsigned b, unsigned d) : a(a), b(b), d(d) { }
  contract(const contract& c, unsigned t) : a(c.a), b(c.b), d(c.d), t(t) { }
};

struct order_d {
  bool operator () (const contract& c1, const contract& c2) {
    // d ASC, a ASC - reversed because priority_queue
    if(c1.d != c2.d) return c1.d > c2.d;
    return c1.a > c2.a;
  }
};

struct order_a {
  bool operator () (const contract& c1, const contract& c2) {
    // a DESC, t ASC - reversed because priority_queue
    if(c1.a != c2.a) return c1.a < c2.a;
    return c1.t > c2.t;
  }
};

int main()
{
  // input contracts
  int N; cin >> N;
  priority_queue<contract, vector<contract>, order_d > cs;
  while(N-- > 0) {
    unsigned a, b, d; cin >> a >> b >> d;
    cs.push(contract(a, b, d));
  }
  
  // scheduling phase
  priority_queue<contract, vector<contract>, order_a > finished;
    // ^ contains only time-reducible contracts (t > 0) to reduce computation
  double payment = 0.0;
  unsigned start_time = 0;
  while(! cs.empty()) {
    const contract c = cs.top(); cs.pop();
    if(start_time + c.b > c.d) {
      finished.push(contract(c, c.b));
      // greedy optimization loop
      unsigned dt = start_time + c.b - c.d;
      //cerr << "reducing time = " << dt << endl;
      while(dt > 0 && ! finished.empty()) {
        contract r = finished.top(); finished.pop();
        unsigned tm = min(r.t, dt);
        //cerr << " ct a=" << r.a << " t=" << r.t << " / tm=" << tm << endl;
        payment += (double)tm / r.a;
        if(r.t - tm > 0)
          finished.push(contract(r, r.t - tm));
        dt -= tm;
      }
      assert(dt == 0); // impossible case
      
      start_time = c.d;
    } else {
      // no need to reduce time
      finished.push(contract(c, c.b));
      start_time += c.b;
    }
  }
  
  // result
  static char buffer[16384];
  snprintf(buffer, sizeof buffer, "%.2lf", payment);
  cout << buffer << endl;
  return 0;
}