Bài 1:

program min;
uses crt;
var a, b, c, d: integer;
begin
clrscr;
write('nhap so a :'); readln(a);
write('nhap so b :'); readln(b);
write('nhap so c :'); readln(c);
write('nhap so d :'); readln(d);
if (a<b) and (a<c) and (a<d) then writeln(a,' la so be nhat');
if (b<a) and (b<c) and (b<d) then writeln(b,' la so be nhat');
if (c<a) and (c<b) and (c<d) then writeln(c,' la so be nhat');
if (d<a) and (d<b) and (d<c) then writeln(d,' la so be nhat');
readln
end.

Bài 2:

program am_duong;

uses crt;

var a: integer;

begin

clrscr;

write('nhap so a :');readln(a);

if (a>0) then writeln(a,' la so duong');

if (a<0) then writeln(a,' la so am');

if a = 0 then writeln( a,' khong duong khong am');

readln

end.

Bài 3:

program chan_le;

uses crt;

var a: integer;

begin

clrscr;

write('nhap so a :');readln(a);

if (a mod 2 = 0) then writeln(a,' la so chan')

else writeln(a,' la so le');

readln

end.