Bài 1:

Uses crt;

var i,n,j:integer;

     a,b,c:array[1..100000] of integer;

Begin

clrscr;

readln(n);

for i:= 1 to n do readln(a[i]);

for i:= 1 to n do readln(b[i]);

j:=0;

for i:= 1 to n do 

  Begin

  inc(j);

  c[j] := a[i];

  inc(j);

  c[j] := b[i];

  end;

for i:= 1 to j do write(c[i],'  ');

readln;

end. 

Program Tin_hoc;

uses crt;

var n,i,dem:integer;

      a:array[1..10000] of integer;

Begin

clrscr;

readln(n);

dem:=0;

for i:= 1 to n do 

  Begin

  readln(a[i]);

  if a[i] mod 2 = 0 then inc(dem);

  end;

writeln('Day so co ',dem,' so chan');

readln;

end.

Có thể bỏ uoc:=0; tam:=0 ở dòng thứ 5 nha

Uses crt;
var i,n,uoc,j,tam:longint;
Begin
clrscr;
readln(n);uoc:=0;tam:=0;
for i:= 1 to n do if n mod i = 0 then inc(uoc);
if uoc = 2 then write(n,' la so nguyen to')
 else for i:= 2 to n do if n mod i = 0 then
   begin
   tam:=0;
   for j:= 1 to i do if i mod j = 0 then inc(tam);
   if tam = 2 then write(i,'  ');
   end;
readln;
end.

Có chỗ nào sai thì bảo mình

Uses crt;

var i,n,dem:integer;

Begin

clrscr;

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

dem:=0;

for i:= 1 to n do

  begin

  if i mod 2 = 1 then 

    begin

    write(i,'   ');

    inc(dem);

    end;

  if dem mod 15 = 0 then writeln;

  end;

Readln;

End.

Uses crt;

var i,n:longint;

     S,A:real;

begin

clrscr;

Readln(A);

S:=0;n:=0;

while S<=A do

  Begin

  S:=0; 

  inc(n);

  for i:= 1 to n do S:=S+1/i;

  end;

Writeln(n);

readln;

end.

Program Tin_hoc;

Uses crt;

var s:string;

      i,dem:integer;

Begin

clrscr;

dem:=0;

Write('Nhap xau: ');readln(s);

for i:= 1 to length(s) do if (s[i]='a') or (s[i]='e') or (s[i]='i') or (s[i]='o') or (s[i]='u') or (s[i]='y') then inc(dem);

Writeln('Xau vua nhap co ',dem,' nguyen am');

readln;

end.

Uses crt;
var f1,f2:text;
    i,n,tong,tongchan,dem:integer;
    tb:real;
Begin
 clrscr;
 Assign(f1,'DAYSO.txt');
 Assign(f2,'KETQUA.txt');
 reset(f1);dem:=0;tong:=0;tongchan:=0;
 While Not EOF(f1) do
  Begin
  read(f1,i);
  inc(tong,i);
  If i mod 2 = 0 then
    begin
    inc(dem);
    inc(tongchan,i);
    end;
  End;
 tb:=tongchan/dem;
 close(f1);
 rewrite(f2);
 writeln(f2,tong);
 writeln(f2,tongchan);
 writeln(f2,tb:0:2);
 close(f2);
 write(tong);
 readln;
End.

Uses crt;

var i,a,b,tam:integer;

Begin

 clrscr;

 Write('Nhap 2 so a,b: ');readln((a,b);

 If a>b then

   begin

   a:=a*2;

   b:=b*2;

   End

 else if a<b

   begin

   tam:=a;

   a:=b;

   b:=tam;

   End;

 readln;

End.