Câu 2: 

program Min;
uses crt;
var A:array[1..10000] of integer;
    S,i,n:integer;
begin
   clrscr;
   S:=0;
   write('Nhap so phan tu cua mang: '); readln(n);
   for i:=1 to n do
   begin
      write('Nhap phan tu thu ',i,': ');
      readln(A[i]);
   end;
   for i:=1 to n do if A[i] mod 2 = 0 then S:=S+A[i];
   write('Tong cac phan tu chan la: ',S);
   readln
end.

Câu 3: 

program Min;
uses crt;
var A:array[1..10000] of integer;
    i,n:integer;
begin
   clrscr;
   write('Nhap so phan tu cua mang: '); readln(n);
   for i:=1 to n do
   begin
      write('Nhap phan tu thu ',i,': ');
      readln(A[i]);
   end;
   for i:=1 to n do if A[i] mod 3 = 0 then write(A[i]:4);
   readln
end.

Câu 4: 

program Min;
uses crt;
var A:array[1..10000] of integer;
    i,n,dem:integer;
begin
   clrscr;
   write('Nhap so phan tu cua mang: '); readln(n);
   for i:=1 to n do
   begin
      write('Nhap phan tu thu ',i,': ');
      readln(A[i]);
   end;
   for i:=1 to n do if (A[i] mod 3 = 0) and (A[i] mod 5 = 0) then inc(dem);
   readln
end.