2 câu trả lời
Program viet_chuong_trinh_tong;
uses crt;
var n,i,s:integer;
Begin
Clrscr;
write('nhap so :');
readln(n);
S:=0;
for i:=1 to n do S:=S+i;
Write('Tong cua 1+2+3+=',S);
readln;
End.
Program TinhTong;
Uses crt;
Var N,i,S:integer;
Begin
Clrscr;
Write('Nhap vao gia tri cua N :');
S:=0;
For i:=1 to N do S:=S+i;
Writeln('Ket qua la :',S);
Readln;
End.