Dùng while-do:
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.
${Oken}$