Playing With Numbers

Fill in the blanks
a)A number is divisible by $$24$$ if it is divisible by both ____ and ____.
b)A number is divisible by ____ if it is divisible by $$4$$ and $$9$$.
In each of the following questions, the numbers/letters are arranged based on some pattern or principle.Choose the correct answer for the term marked by the symbol (?) 
If a number is divisible by any number m , then it will also be divisible by each of the factor m'. This statement is _____ .
Solve:
$$\frac{12^{3}\times 9^{2}\times 4}{6^{4}\times 8^{2}\times 8}.$$
Observe the given pattern
$$4\times 0+1=01$$
$$4\times1+2=06$$ 
$$4\times 2+3=11$$
$$4\times 3+4=16$$
Then the value of $$4\times8+9 $$ is -----