$A$ and $B$ are 2 × 3 matrices and $C$ is a 3 × 2 matrix. Which of the following is NOT defined?

Explanation

1. 01

   Matrices can be added or subtracted only when they have the same order.

2. 02

   $A$, $B$, $2B$ and $3A$ are all 2 × 3, but $C$ is 3 × 2, so $A + C$ is not defined.