S = 1 + 3 + 5+...+ n( bằng while do)
uses crt;
var i,n,s: integer;
begin
clrscr;
write ('nhap n: '); readln (n);
while i<=n do
begin
i:=i+1;
if i mod 2<>0 then s:=s+i;
end;
write ('tong la: ',s);
readln;
end.
S = 2 + 4 + 6 +...n( bằng while do)
uses crt;
var i,n,s: integer;
begin
clrscr;
write ('nhap n: '); readln (n);
while i<=n do
begin
i:=i+1;
if i mod 2=0 then s:=s+i;
end;
write ('tong la: ',s);
readln;
end.