Bài 1:
uses crt;
var n,kq,i:integer;
begin
clrscr;
write('Nhap n: '); readln(n);
for i:=1 to n do
kq:=kq+i;
write('Tong la: ',kq);
readln;
end.
Bài 2:
uses crt;
var n,kq,i:longint;
begin
clrscr;
kq:=1;
write('Nhap n: '); readln(n);
for i:=1 to n do
kq:=kq*i;
write('Tong la: ',kq);
readln;
end.
Bài 3:
uses crt;
var kq,i:longint;
begin
clrscr;
for i:=1 to 20 do
if i mod 2 = 0 then kq:=kq+i;
write('Tong la so chan 1 den 20 la: ',kq);
readln;
end.
Bài 4:
uses crt;
var kq,i:longint;
begin
clrscr;
for i:=1 to 20 do
if not i mod 2 = 0 then kq:=kq+i;
write('Tong la so chan 1 den 20 le: ',kq);
readln;
end.