Question

If $A$ is a $4\times 4$ matrix and $|A|=5$, then find the value of $|4A|$.

• A. $1280$
• B. $320$
• C. $20$
• D. $5120$

Answer 1

The correct option is A $1280$

For any matrix of order $n,|kA|=k^n|A|\Rightarrow |4A|=4^4|A|=256\times 5=1280$