write a c++ program using class to calculate simple interest amount use default value for rate

/*write a c++ program using class to calculate simple interest amount use
default value for rate*/
#include<iostream.h>
#include<conio.h>
class interest
{
int prin,nof;
float rof,si;
public:void getdata(int p,int n,float r=10.222)
       {
       prin=p;
       nof=n;
       rof=r;
       }
       void display()
       {
       si=prin*nof*rof;
       cout<<"\nsimple interest is:-"<<si;
       }
};
int main()
{
interest in1,in2;
clrscr();
in1.getdata(200,12);
in1.display();
in2.getdata(120,4);
in2.display();
getch();
return 0;
}
/*
simple interest is:-24532.800781
simple interest is:-4906.560059
*/