Question

sa se calculeze combinari luate cate 3 din 7

Answer 1

$C^3_7 = C^{(7-3)}_7= C^4_7 = \frac{7!}{3! * 4!}= \\ =\frac{1*2*3*4*5*6*7}{1*2*3*1*2*3*4}= \frac{5*6*7}{1*2*3}= \\ = \frac{5*6*7}{6}=5*7=35$

Answer 2

Daca te referi la combinari de 7 luate cite trei atunci rezulta
$\frac{7!}{3!(7-3)!} =35$