If A is a 3 × 3 matrix such that |A| ≠ 0 and |3A| = k|A| then write the value of k.
Theorem: If Let A be k × k matrix then |pA|=pk|A|.
Given: k=3 and p=3.
|3A|=33 × |A|
=27|A|.
Comparing above with k|A| gives k=27.