Question

If A is an m × n matrix and B is n × p matrix does AB exist? If yes, write its order.

Answer 1

Given: Order of A = $m\times n$
Order of B = $n\times p$

Since the number of columns in A are equal to the number of rows in B, i.e. n, AB exists.
Order of AB = Number of rows in A$\times$ Number of columns in B
= $m\times p$