新手在国外刚开始学习 上课听不懂 下面要求一组平均速度保留一位小数 死活算不对

#include <iostream>
#include <stdlib.h>
#include <iomanip>
using namespace std;

int main()
{
    int ss; //SchimmenSekunden
    int rs; //RadfahrenSkunden
    int ls; //LaufenSekunden

    cout << "Zeit Schwimmen (s) : ";
    cin >> ss;
    cout << "Zeit Radfahren (s) : ";
    cin >> rs;
    cout << "Zeit Laufen (s) : ";
    cin >> ls;
    cout << endl;

    int zs = ss / 60; //ZeitSchwimmen
    int zr = rs / 60; //ZeitRadfahren
    int zl = ls / 60; //ZeitLaufen

    int rw = ss % 60; //restMinSchwimmen
    int rr = rs % 60; //restMinRadfahren
    int rl = ls % 60; //restMinLaufen

    double gs = 3.86 / (ss / 3600); //Geschw.schwimmen
    double gr = 180 / (rs / 3600); //Geschw.radfahren
    double gl = 42.2 / (ls / 3600); //Geschw.laufen

    cout << "Zeit Schwimmen : " << zs << " Min " << rw << " Sek, " << " Gschw.  " << setprecision(3) << gs << " km/h " << endl;
    cout << "Zeit Radfahren : " << zr << " Min " << rr << " Sek, " << " Gschw.  " << setprecision(3) << gr << " km/h " << endl;
    cout << "Zeit Laufen : " << zl << " Min " << rl << " Sek, " << " Gschw.  " << setprecision(3) << gl << " km/h " << endl;
    cout << endl;

    double dg = 226.06 / ((ss + rs + ls) / 3600);

    cout << "Durchschnittsgeschwindigkeit : " << setprecision(3) << dg << endl;

    system("pause");

    return 0;