Question

If the order of matrices $A$ and $B$ are $3\times 2$ and $2\times 1$ respectively then find the order of matrix (if possible) $AB$

• A. $1\times 3$
• B. $3\times 1$
• C. $1\times 2$
• D. $3\times 2$

Answer 1

The correct option is B $3\times 1$

When we multiply a matrix A of order $m\times a$ with another matrix B of order $a\times n$, the resultant product matrix $A\times B$ will have the order $m\times n$
So, when we multiply a matrix A of order $3\times 2$ with another matrix of order $2\times 1$, the resultant product matrix $A\times B$ will have the order $3\times 1$