Câu 1:

uses crt;

var i: integer;

s: real;

begin

clrscr;

s:=0;

for i:=1 to 20 do

if i mod 2=0 then s:=s+1/i;

writeln ('tong la: ',s:1:2);

readln;

end.

Câu 2:

uses crt;

var cc: array[1..100] of real;

i,n: integer;

s: real;

begin

clrscr;

write ('nhap so luong: ');  readln (n);

s:=0;

for i:=1 to n do 

begin

write ('nhap chieu cao ban thu ',i,': ');  readln (cc[i]);

s:=s+cc[i];

end;

writeln ('Chieu cao trung binh: ',s/n:1:2);

readln;

end,

C++

Tham khảo :

1)

#include <iostream>
using namespace std;
int main(){
    float s ;
    for (int i=1;i<=20;i++){
        if (i%2==0) s += (1.0/i) ; 
    }
    cout << s ;
}

2)

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