Нужно решить 2, 3, 5, 6 номера

2.

var i,s:integer;

begin

for i:=10 to 20 do

s+=i;

write(s);

end.

3.

var

   factorial: longint;

   n, i: byte;

 begin

   write('n = '); readln(n);

     factorial := 1;

     for i:=2 to n do

       factorial := factorial * i;

     writeln('n! = ', factorial);

readln;

end.

6.

program for_;

uses crt;

var i,s:integer;

begin

clrscr;s:=1;

for i:=1 to 16 do

s:=s*i;

writeln(s);

end.