1)
uses crt;
var n,i:longint; s:real;
begin
clrscr;
write('n=');readln(n);
for i:=1 to n do s:=s+i*i;
writeln('S= ',s:0:0);
readln
end.
2)
uses crt;
var n,i:longint; P:real;
begin
clrscr;
write('n=');readln(n);
for i:=1 to n do p:=p+1/i;
writeln('P= ',p);
readln
end.
3)
uses crt;
var n,i:longint; P:real;
begin
clrscr;
write('n=');readln(n);
for i:=1 to n do p:=p+i*(i+1);
writeln('P= ',p:0:2);
readln
end.
4)
uses crt;
var n,t,t1,i:longint;
begin
clrscr;
write('n=');readln(n);
for i:=1 to n do begin if i mod 2=1 then inc(t,i); if i mod 3=0 then inc(t1,i); end;
writeln('Tong cac so le tu 1->n la: ',t);
writeln('Tong cac so ci het co 3 tu 1->n la: ',t1);
readln
end.
