Answer
The product, if defined,
has the same number of rows as the first matrix,
and the same number of columns as the second matrix,
Work Step by Step
To multiply two matrices,
the first must have as many columns as the other has rows.
The product of an $m\times n$ matrix $A$ and an $n\times p$ matrix $B$
is an $m\times p$ matrix $AB$.
The product, if defined,
has the same number of rows as the first matrix,
and the same number of columns as the second matrix,
