2 câu trả lời
uses crt;
var n,i:longint;s:real;
begin
clrscr;
write('nhap n:');readln(n);
s:=0;
for i:=1 to n do s:=s+(1/(i*2));
write('s=',s:4:2);
readln
end.
$#Zen$
program bt;
Var
N,i:integer;
S:real;
Begin
write('Nhap N: '); readln(n);
S:=0;
For i:=1 to n do if I mod 2=0 then S:=S+1/i;
write(S:5:2);
Readln;
End.
