Question

Encontre o valor da Combinação C(20;2). *
a) 380
b) 190
c) 360
d) 180

Answer 1

Explicação passo-a-passo:

$\sf \dbinom{20}{2}=\dfrac{20!}{2!\cdot(20-2)!}$

$\sf \dbinom{20}{2}=\dfrac{20!}{2!\cdot18!}$

$\sf \dbinom{20}{2}=\dfrac{20\cdot19\cdot18!}{2!\cdot18!}$

$\sf \dbinom{20}{2}=\dfrac{20\cdot19}{2!}$

$\sf \dbinom{20}{2}=\dfrac{380}{2}$

$\sf \dbinom{20}{2}=190$

Letra B

Answer 2

Resposta:

OI!

A alternativa é a letra A