de_2.cpp

#include <bits/stdc++.h>
using namespace std;

int main() {
  int n, a[50], odd = 0, sum = 0, cnt = 0;
  cout << "Nhap n: "; cin >> n;
  for (int i = 0; i < n; i++) {
    cout << "Nhap a[" << i << "]: "; cin >> a[i];
    if (a[i] % 2 == 1) odd++;
    if (a[i] % 6 == 0) {
      sum += a[i]; cnt++;
    }
  }
  cout << "So so le: " << odd << endl;
  if (cnt == 0) cout << "Khong chua so le boi 3";
  else cout << "TBC cac so le boi 3: " << (float) sum / cnt;
}