B1:
program B1;
uses crt;
var A:array [1..500] of integer;
n,i,T: integer;
Begin
clrscr;
write('Nhap n: '); readln(n);
for i:=1 to n do
if i mod 2=0 then T:=T+i;
write('Tong cac so chan = ',T);
readln
End.
B2:
program B2;
uses crt;
var A:array [1..500] of integer;
n,i,T: integer;
Begin
clrscr;
write('Nhap do dai mang: '); readln(n);
for i:=1 to n do
begin
write('A[',i,']='); readln(A[i]);
if A[i] mod 2=0 then T:=T+A[i];
end;
write('Tong cac so chan = ',T);
readln
End.
B3:
program B3;
uses crt;
var A:array [1..500] of integer;
n,i,T: integer;
Begin
clrscr;
write('Nhap do dai mang: '); readln(n);
for i:=1 to n do
begin
write('A[',i,']='); readln(A[i]);
T:=T+A[i];
end;
write('Gia tri trung binh cua day = ',T/n:2:1);
readln
End.