program bai_giai;
uses crt;
var a:array[1..1000]of real;n,i:longint;tbc,s:real;
begin
 clrscr;
  write('Co bao nhieu hoc sinh:');readln(n);
  s:=0;
  for i:=1 to n do
        begin
         write('diem hoc sinh ',i,':');readln(a[i]);
         s:=s+a[i];
        end;
  tbc:=s/n;
  writeln('trung binh cong diem thi cua 3 hoc sinh la: ',tbc:4:2);
  if(tbc>=5)then write('dat')else write('khong dat');
 readln;
end.

uses crt;

var a : array[1..100] of real;

i, n : integer; tb, x : real;

begin

clrscr;

x := 0;

write('Co bao nhieu hoc sinh :');readln(n);

for i := 1 to n do

begin

write('diem hoc sinh ', i ,' : ');readln(a[i]);

x := x + a[i];

end;

tb := x / n;

writeln('Trung binh cong diem thi cua 3 hoc sinh la :', tb:3:1);

if tb >= 5 then writeln('Dat') else writeln('Khong dat');

readln

end.