- Chương trình 1 :

uses crt;

var n, k : longint;

function c(x, y : longint) : real;

var i, d1, d2, d3 : longint;

begin

d1 := 1; d2 := 1; d3 := 1;

for i := 1 to x do d1 := d1 * i;

for i := 1 to y do d2 := d2 * i;

for i := 1 to x - y do d3 := d3 * i;

c := d1 / (d2 * d3);

end;

begin

clrscr;

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

if k <= n then

write('To hop chap ', k ,' cua ', n ,' = ', c(n, k) : 2 : 0);

readln

end.

- Chương trình 2 :

uses crt;

var n, k : longint;

function P(x, y : longint) : real;

var i, d1, d3 : longint;

begin

d1 := 1; d3 := 1;

for i := 1 to x do d1 := d1 * i;

for i := 1 to x - y do d3 := d3 * i;

P := d1 / d3;

end;

begin

clrscr;

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

if k <= n then

write('Chinh hop chap ', k ,' cua ', n ,' = ', P(n, k) : 2 : 0);

readln

end.

uses crt;

var n,k,c,p: real;

function gt(n: integer): longint;

var i: integer;

s: longint;

begin

s:=1;

for i:=1 to n do

s:=s*i;

gt:=s;

end;

begin

clrscr;

write ('nhap n: ');   readln (n);

write ('nhap k: ');  readln (k);

c:=gt(n)/(gt(k)*gt(n-k));

p:=gt(n)/gt(n-k);

writeln ('C=',c:1:2);

writeln ('P=',p:1:2);

readln;

end.