#include <iostream>
using namespace std;
int main(){
    long n;
    cin >> n;
    long a[n],tong=0,tich=1;
    for (long i=0; i<n; i++){
        cin >> a[i];
        tong=tong+a[i];
        tich=tich*a[i];
    }
    double tbc=(double)tong/n;
    cout << "Tong: " << tong << endl << "Tich: " << tich << endl << "TBC: " << tbc << endl;
}

$\color{red}{\text{#Daoanhviet96}}$

#include <iostream>
using namespace std;
int main()
{
    int n,s,tong,tich;
    int a[1000];
    cout << "Nhap do dai cua day: ";
    cin >> n;
    for (int i=1; i<=n; i++) {
        cout << "a[" << i << "]= ";
        cin >> a[i];
        s = s+a[i];
        tich = tich*a[i];
        tong = tong+a[i];
    }
    cout << "TONG = " << tong << "\n";
    cout << "TICH = " << tich << "\n";
    cout << "TRUNG BINH CONG = " << s/n << "\n";
    return 0;
}