Câu 2:
uses crt;
var i,kq:longint;
begin
clrscr;
for i:=1 to 10 do
if i mod 2 = 0 then
kq:=kq+i;
write('Tong so chan tu 1 den 10: ',kq);
readln;
end.
Câu 3:
uses crt;
var i,kq:longint;
begin
clrscr;
for i:=1 to 10 do
if not i mod 2 = 0 then
kq:=kq+i;
write('Tong so le tu 1 den 10: ',kq);
readln;
end.