a) bez zwracania

$\Omega =\left\{\left(1,2\right),\left(1,3\right),\left(1,4\right),\left(2,1\right),\left(2,3\right),\left(2,4\right),\left(3,1\right),\left(3,2\right),\left(3,4\right),\left(4,1\right),\left(4,2\right),\left(4,3\right)\right\}$