If A is a square matrix and | A | = 2, then write the value of | AA’ |, where A’ is the transpose of matrix A.
| AA’ | = 4 

If A and B are square matrices of order 3 such that |A| = –1, |B| = 3, then find the value of |2AB|.
If A is an invertible square matrix of order 3 and |A| = 5, then find the value of |adj A|.
If A = {1, 2, 3}, B = {4, 5, 6, 7} and f = {(1, 4), (2, 5),(3, 6)} is a function from A to B. State whether f is one-one or not.
State the reason why the Relation R = {(a, b) : a ≤ b²} on the set R of real numbers is not reflexive.