Question

Com os algarismo 1,2,3,4,5,6,7,8 e 9:
a)quantos numeros naturais de 4 algarismo podemos ser formados?
b)quantos numeros naturais pares 3 algarismo dististos existem ? 


Me ajudem , Beijinhos :*

Answer 1

$a)\\\\\boxed{1\º}~~\boxed{2\º}~~\boxed{3\º}~~\boxed{4\º}\\\\9~~~.~~~9~~~.~~9~~.~~~9~~=\boxed{6561~~n\'umeros}$

$b)\\\\\boxed{1\º}~~\boxed{2\º}~~\boxed{3\º}\\\\~~8~~~.~~7~~.~~4~~=~~\boxed{224~~n\'umeros}$