bài 1:
program oken;
uses crt;
var n,i,dem:integer;
begin
clrscr;
write('nhap n: '); readln(n);
dem:=0;
write('cac so le tu 1 den ',n,': ');
for i:=1 to n do
if i mod 2=1 then
begin
write(i,' ');
dem:=dem+1;
end;
writeln;
writeln('co ',dem,' so len');
readln;
end.
bài 2:
program oken;
uses crt;
var n,i,tong:longint;
begin
clrscr;
write('nhap n: '); readln(n);
tong:=0;
for i:=1 to n do
if i mod 2=0 then
tong:=tong+i;
writeln('tong so chan: ',tong);
readln;
end.
