VTMO 2016 — Grade 6 — final Question 2

$a$)Find a six-digit number $N$ using only $8 , 9$ divisible by $2^{6}$. $b$)Use each digit $1 \text{--} 9$ once in three three-digit integers $a : b : c = 1 : 3 : 5$. Find $a , b , c$.