$BT2$

Program Hotboy;

Uses crt;

Var a:array[1..100] of integer ;

I,n,s: longint;

Begin

Clrscr;

Write('nhap so phan tu cua mang'); readln(n);

For i:=1 to n do 

Begin

Write('A[',i,']'); readln(A[i]);

End;

For i:=1 to n do 

S:=S+A[i];

Write('tong cac so trong mang la',S);

Readln

End.

$BT3$

Program Hotboy;

Uses crt;

Var a:array[1..200] of integer ;

I,n: longint;

Begin

Clrscr;

Write('nhap so phan tu cua mang'); readln(n);

For i:=1 to n do 

Begin

Write('A[',i,']'); readln(A[i]);

End;

For i:=1 to n do 

If ( A[i] mod 2=0) then Write(A[i],la phan tu chan);

Readln

End.

2.

#include <iostream>
using namespace std;
int main(){
    int n,tt=0;
    cin>>n;
    int arr[n];
    for(int i=0;i<n;i++){
        cin>>arr[i];
        tt+=arr[i];
    }
    cout<<tt;
    //samon247
    return 0;
}

3.

#include <iostream>
using namespace std;
int main(){
    int n,tt=0;
    cin>>n;
    int arr[n];
    for(int i=0;i<n;i++){
        cin>>arr[i];
        if(arr[i]%2==0){
            tt+=arr[i];
        }
    }
    cout<<"Tong chan: "<<tt;
    //samon247
    return 0;
}