Question

Find the product AB, if possible.

Answer 1

first, what is the "shape" of A, as in # of rows by # of columns?

Answer 2

2 & 3

Answer 3

A is 2 x 3
B is 3 x 1

if the "numbers match" for A B as in 2 x 3 x 3 x 1 you can do the problem
the final answer will be the outer numbers: 2 x 1 2 rows by 1 column

notice BA will not work 3 x 1 x 2 x 3 the inner numbers 1 x 2 do not match.