If you think your code produces the correct results on the inputs you've tried, maybe you could say what your code does to us, step by step. We could then see where you have a mistaken understanding.

But that wouldn't give the right result. It would give 0.50 if the number of days was 25. But on the 25th day, the person would earn 167772.16.

C++ Syntax (Toggle Plain Text)

#include <iostream>
#include <string>
#include <iomanip>
using namespace std;
 
int main ()
{
	int days, firstday;
    double numPay = .01;
    double total = 0;
 
 
 
		cout << "How many days did you work?: ";
		cin >> days;
		cout <<"\n";
			while (days <1 || days>31)
				 {cout << "That is an invalid days selection, please select 1-31: ";
				  cin >> days;}
			firstday=1;
 
			cout<<"Day"<<"\t\t"<<"Amount Earned"<<endl;
			cout<<"----------------------------"<<endl;
 
			while (firstday<=days)
			{cout<< firstday <<"\t\t\t"<< numPay <<endl;
          numPay = numPay *2;
          firstday++;
		  }
		  total=numPay-0.01;
          cout<<" "<<endl;
          cout<< fixed << showpoint << setprecision(2);
          cout<<" Total Amount To Be Paid Is $"<<"\t"<< total << endl;
          cout<<" "<<endl;
          return 0;
          }

#include <iostream> #include <string> #include <iomanip> using namespace std; int main () { int days, firstday; double numPay = .01; double total = 0; cout << "How many days did you work?: "; cin >> days; cout <<"\n"; while (days <1 || days>31) {cout << "That is an invalid days selection, please select 1-31: "; cin >> days;} firstday=1; cout<<"Day"<<"\t\t"<<"Amount Earned"<<endl; cout<<"----------------------------"<<endl; while (firstday<=days) {cout<< firstday <<"\t\t\t"<< numPay <<endl; numPay = numPay *2; firstday++; } total=numPay-0.01; cout<<" "<<endl; cout<< fixed << showpoint << setprecision(2); cout<<" Total Amount To Be Paid Is $"<<"\t"<< total << endl; cout<<" "<<endl; return 0; }