- Chương trình a :

uses crt;

var i, n, S : integer;

begin

clrscr;

write('Nhap so n : '); readln(n);

S := 0; for i := 1 to n do S := S + i;

write('S = ', S);

readln

end.

- Chương trình b :

uses crt;

var i, n : integer; S : real;

begin

clrscr;

write('Nhap so n : '); readln(n);

S := 0; for i := 1 to n do S := S + 1 / i;

write('S = ', S : 2 : 2);

readln

end.

- Chương trình c :

uses crt;

var i, n : integer; S : real;

begin

clrscr;

write('Nhap so n : '); readln(n);

S := 0; for i := 0 to n do S := S + 1 / ( i + 1);

write('S = ', S : 2 : 2);

readln

end.

a. S = 1 + 2 + 3 + ... + n

program baitap;
uses crt;
var i,n,s:longint;
begin
clrscr;
write('n=');
readln(n);
for i:=1 to n do
s:=s+i;
writeln('tong: ',s);
readln
end.

b. S = 1 + 1/2 + 1/3 + ... + 1/n

program baitap;
uses crt;
var i,n:longint;
s:real;
begin
clrscr;
write('n=');
readln(n);
for i:=1 to n do
s:=s+1/i;
writeln('tong: ',s:3:2);
readln
end.

c. S = 1 + 1/2 + 1/3 + ... + 1/ (n+1)

program baitap;
uses crt;
var i,n:longint;
s:real;
begin
clrscr;
write('n=');
readln(n);
for i:=1 to n+1 do
s:=s+1/i;
writeln('tong: ',s:3:2);
readln
end.

cre python

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