rogram oken; uses crt; var n,i: integer; s: real; begin clrscr; write('nhap n: '); readln(n); i:=1; while i<=n do begin s:=s+ 1/(i*(i+1)); i:=i+1; end; writeln('Tong S: ',s:0:3); readln; end.
Dùng For-do:
program oken; uses crt; var n,i: integer; s: real; begin clrscr; write('nhap n: '); readln(n); for i:=1 to n do s:=s + 1/(i*(i+1)); writeln('Tong S: ',s:0:3); readln; end.
