The question was to create a class named ACCOUNTS with a read function to accept the sales and purchases and then to create a friend function to print total tax to pay. I have tried doing this, but I keep getting the error that the funtion read and tottax have too few arguments. What can I correct?
#include<stdio.h>
    #include<iostream>
    using namespace std;
    class ACCOUNTS
    {   
        public:
        ACCOUNTS(){sales=0,purchase=0;}
        private:
            int sales,purchase;
        friend void tottax(ACCOUNTS &sfo);
        friend void read(ACCOUNTS &sfo);
    };
        void read(ACCOUNTS &sfo)
        {
            cout<<"Enter saleamt : \n";
            cin>>sfo.sales;
            cout<<"Enter purchaseamt : \n";
            cin>>sfo.purchase;
        }
        void tottax(ACCOUNTS &sfo)
        {
            int tax=(sfo.sales-sfo.purchase)*(4/100);
            cout<<"\nTax : "<<tax;
        }
        int main()
        {
            read();
            tottax();
            return 0;
        }
 
    