20_sentinel_controlled_program.cpp

#include<iostream>
using namespace std;

int main(){
	int age;
	int ageTotal = 0;
	int numberOfPeopleEntered = 0;
	
	cout << "Enter first person's age pr -1 to quit " << endl;
	cin >> age;
	
	while(age != -1){
		ageTotal = ageTotal + age;
		numberOfPeopleEntered++;
		
		cout << "Enter next person's age or -1 to quit" << endl;
		cin >> age;
	}
	
	cout << "Number of people entered: " << numberOfPeopleEntered << endl;
	cout << "Average age: " << ageTotal/numberOfPeopleEntered << endl;
	
	return 0;
}