Câu 1 :

uses crt;

var sum, i, n : integer;

begin

clrscr;

write('Nhap so n : '); readln(n);

while n <= 0 do

begin write('Nhap lai so n : ');

readln(n); end;

sum := 0; for i := 1 to n do

if i mod 2 <> 0 then sum := sum + i;

write('Tong = ', sum);

readln

end.

Câu 2 :

uses crt;

var i, n, c, j : integer;

begin

clrscr;

c := 0;

write('Nhap so n : '); readln(n);

write('Cac so nguyen to : ');

for j := 2 to n do begin

for i := 1 to n do

if j mod i = 0 then c := c + 1;

if c = 2 then write(j,'   ');

c := 0; end;

readln

end.

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Câu 1: Hình 1

Câu 2: Hình 2