Question

C= 12 ,3 ???????????

Answer 1

Combinação

$\boxed{C_{n,p} = \frac{n!}{p!(n-p)!}}$

Então, temos que:

$C_{12,3}=\frac{12!}{3!(12-3)!}\\\\ C_{12.3}=\frac{12!}{3!9!}\\ \\ C_{12,3}=\frac{12*11*10*9!}{3!9!}$

$\ \\ C_{12,3}=\frac{12*11*10}{6}\\\\ \large\boxed{C_{12.3}=220}$

Answer 2

C12,3 = 12! / (12-3)3! = 12 x 11 x 10 x 9!/ 9! 3! (corta o 9! de cima e o de baixo) = 1320/6 = 220