main.cpp

#include <iostream>
#include <cmath>
using namespace std;

int main() {
	double revenue;
	double costs;
	double tax;

	cout << "What is the revenue?\n";
	cin >> revenue;
	cout << "What were the costs?\n";
	cin >> costs;
	cout << "What is the tax rate (%)?\n";
	cin >> tax;

	double grossProfit = revenue-costs;
	double netProfit;
	if (grossProfit>0) {
		netProfit = grossProfit * (1 - 0.01*tax);
	} else {
		netProfit = grossProfit;
	}

	cout << "Net profit is ";
	cout << netProfit << "\n";
	return 0;
}