1/

uses crt;

var i,n,s: integer;

begin

clrscr;

write ('nhap n: ');  readln (n);

for i:=1 to n do

if i mod 2=0 then s:=s+i;

writeln ('tong cac so chan tu 1-->n la: ',s);

readln;

end.

2/

uses crt;

var i,n,s: integer;

begin

clrscr;

write ('nhap n: ');  readln (n);

for i:=1 to n do

if i mod 2<>0 then s:=s+i;

writeln ('tong cac so le tu 1-->n la: ',s);

readln;

end.

3/

uses crt;

var m,n,t,i: integer;

begin

clrscr;

write ('nhap m: ');  readln (m);

write ('nhap n: ');  readln (n);

if m>n then

begin

for i:=n to m do

if i mod 2=0 then s:=s+i;

end

else

for i:=m to n do

if i mod 2=0 then s:=s+i;

writeln ('tong cac so chan la: ',s);

readln;

end.

4/

uses crt;

var t,i,n: integer;

begin

clrscr;

repeat

i:=i+1;

t:=t+i;

n:=i;

until  t>1000;

writeln ('n nho nhat de T lon hon 1000 la: ',n);

readln;

end.

5/

uses crt;

var n: integer;

begin

clrscr;

n:=1000;

repeat

n:=n-1;

until 1/n<0.003;

writeln ('n nho nhat de 1/n <0.003: ',n)

readln;

end.

<Chương trình gộp>

program phuongt;

uses crt;

  var s, n, i, t, m: integer;

  const a=0.003;

begin

          clrscr;

          write('Nhap n = '); readln(n);

          write('Nhap m ='); readln(m);

          s:=0;

          for i:=1 to n do if i mod 2 = 0 then s:=s+i;

          write('Tong chan: ', s);

          s:=0;

          for i:=1 to n do if i mod 2 = 1 then s:=s+i;

          write('Tong le: ', s);

          s:=0;

          for i:=m to n do if m mod 2 = 0 then s:=s+m;

          write('Tong chan tu m den n: ', s);

          t:=0; n:=0;

          while t<1000 do

          begin

                    n:=n+1;

                    t:=t+n;

          end;

          write('n nho nhat: ', n);

          n:=0; m:=1;

          while m>=a do

          begin

                      m:=1/n;

                      n:=n+1;

          end;

          write('So n nho nhat de 1/n<0.003: ', n-1);

          readln

end.