Finding with matrices just practicing for my advanced Hong Kong diploma and I've found some matrices problems I'd like to look at. Usually quite comfortable with these but have found some I'm not so sure on. In terms of what they are asking.
I have some matrices $$ A = \begin{pmatrix} 2 &0\\  
                       4 &−6\end{pmatrix}, \qquad B = \binom 1{-1} $$      
I need to find 
1) $3A$
2) Half of $A$
3) $2B$
For number one do I just multiply it by itself?
For number two would I simply half the given matrix entries?
For number 3 Do I literally just multiply it by itself also?
So for example for number two I'd have 
$$ \frac 12 A = \begin{pmatrix} 1 &0\\  
                       2 &−3\end{pmatrix} $$

You are right, we have: 
$$ 3A = \begin{pmatrix} 6 &0\\  
                       12 &−18\end{pmatrix}, 
\quad \frac 12 A = \begin{pmatrix} 1 &0\\  
                       2 &−3\end{pmatrix}, \quad 2B = \binom{2}{-2} $$
