1
program ct;
uses crt;
var S,i,n:integer;
begin
clrscr;
write('nhap n:=');readln(n);
S:=0;
for i:=1 to n do S:=S+i;
writeln('tong cu n so tu nhien la:',S);
readln
end.
2.
program ct;
uses crt;
var i,n:integer; tbc:real;
A:array[1..100] of integer;
begin
clrscr;
write('nhap n:=');readln(n);
for i:=1 to n do
begin
write('nhap mang A[',i,']:=');readln(A[i]);
end;
tbc:=0;
for i:=1 to n do
if A[i] mod 2=0 then tbc:=(tbc+A[i])/n;
writeln('trung binh cong la:',tbc);
readln
end.