Answer
$2^n\cdot3$
Work Step by Step
We know that if $A$ and $B$ are $n\times n$ matrices, then $det(AB)=det(A)det(B)$.
We also know that if $A$ is invertible, then $det(A^{-1})=\frac{1}{det(A)}$
We also know that if $A$ is an $n\times n$ matrix, then $det(kA)=k^ndet(A)$
Hence $det(2A)=2^ndet(A)=2^n\cdot3$