Question

Cate variante de alegere a 3 produse diferite de pe un raft cu 11 sortimente , exista?
*E PROBLEMA LA MATE*

Answer 1

$\it C^3_{11}=\dfrac{11!}{3!(11-3)!}=\dfrac{11!}{1\cdot2\cdot3\cdot8!}=\dfrac{8!\cdot9\cdot10\cdot11}{6\cdot8!}=\dfrac{990}{6}=165$