If A is a non singular square matrix of order 3 such that $A^3=4A^2$ then value of |A| is :

16 64 4 8

64

$A^3=4A^2$ so $A^3A^{-1}=4A^2A^{-1}⇒A^2=4A$ post multiplying by $A^{-1}$ $A^2A^{-1}=4AA^{-1}⇒A=4I$ so $|A|=4^3|I|$ as order is 3 so $|A|=64$