Question 4
a) Find the six-digit natural number $N$ formed only from digits 8 and 9 that is divisible by $2^6$.
b) Use digits $1,2,3,\ldots,9$ exactly once altogether to form three three-digit numbers $a,b,c$ such that $a:b:c=1:3:5$. Find $a,b,c$.
b) Use digits $1,2,3,\ldots,9$ exactly once altogether to form three three-digit numbers $a,b,c$ such that $a:b:c=1:3:5$. Find $a,b,c$.