Question

PRECISO RESOLVER ISSO ME AJUDA

Answer 1

$\frac{A_{6,3}+A_{5,4}}{A_{8,5}}=\frac{\frac{6!}{3!}+\frac{5!}{1!}}{\frac{8!}{3!}}=\frac{6.5.4+120}{8.7.6.5.4}=\frac{1}{28}$