Question

Numarul submultimilor cu 3 elemente ale multimilor A={0,1,2,3,4,5}

Answer 1

combinaride 6 luate cate 3=6!/3!*3!=4*5*6/6=4*5=20

Answer 2

$\it C_6^3 = \dfrac{6!}{3!(6-3)!} = \dfrac{3!\cdot4\cdot5\cdot6}{1\cdot2\cdot3\cdot3!} = 20$