Question

If A, B are square matrices of order 3, A is non-singular and AB = O, then B is a
(a) null matrix
(b) singular matrix
(c) unit-matrix
(d) non-singular matrix

Answer 1

$\left(a\right)$ null matrix
Since A is non-singular matrix and the determinant of a non-singular matrix is non-zero, B should be a null matrix.