Question

Dau coroana si 28 de puncte.
Materie clasa a 10 a.
Multumesc anticipat​

Answer 1

Răspuns:

Explicație pas cu pas:

{0,1,2,3,4,5,6,7}

$C_{7}^{0}=\dfrac{7!}{0!*(7-0)!}=\dfrac{7!}{1*7!}=1,~~nu~e~prim\\C_{7}^{1}=\dfrac{7!}{1!*(7-1)!}=\dfrac{7!}{1*6!}=\dfrac{6!*7}{1*6!}=7,~~este~prim\\C_{7}^{2}=\dfrac{7!}{2!*(7-2)!}=\dfrac{7!}{2*5!}=\dfrac{5!*6*7}{2*5!}=21,~nu~este~prim\\C_{7}^{3}=\dfrac{7!}{3!*(7-3)!}=\dfrac{7!}{3!*4!}=\dfrac{4!*5*6*7}{6*4!}=35,~nu~este~prim\\C_{7}^{4}=C_{7}^{7-4}=C_{7}^{3}=35,~nu~este~prim\\C_{7}^{5}=C_{7}^{7-5}=C_{7}^{2}=21,~nu~este~prim\\C_{7}^{6}=C_{7}^{7-6}=C_{7}^{1}=7,~~este~prim$

$C_{7}^{7}=C_{7}^{7-7}=C_{7}^{0}=1,~nu~este~prim$

nr posibil de cazuri, n=8

nr de cazuri favorabile, m=2

P=m/n=2/8=1/4.