Program Hoidap247;
Uses crt;
Var i,n,dem,s : integer;
Begin
If i mod 3= 0 then dem:=dem+1;
end;
for i:=1 to n do
begin
if i mod 3= 0 then S:=s+i;
end;
Writeln('tong cac so tu 1 den N chia het cho 3 la',S);
writeln(' so cac so chia het cho ba la',dem);
Readln
End.
Hoặc :
program Hoidap247;
var n,i.d: integer;
t: longint;
begin
readln(n);
t:=0; d:=0;
for i:=1 to n do
if i mod 3=0 then inc(d);
write('Co ',d,' so chia het cho 3 tu 1 den N');
readln
end.