Question

If $A=\left[a_{i j}\right]_{3 \times 4}$ is matrix given by
$A=\begin{bmatrix} 4 & -2 & 1 & 3 \\ 5 & 7 & 9 & 6 \\ 21 & 15 & 18 & -25 \end{bmatrix}$
Then, $a_{23}+a_{24}$ will be equal to the element

• A. $a_{14}$
• B. $a_{44}$
• C. $a_{13}$
• D. $a_{32}$

Answer 1

Answer: (A)

The given matrix is $A=\begin{bmatrix}4 & -2 & 1 & 3 \\ 5 & 7 & 9 & 6 \\ 21 & 15 & 18 & -25\end{bmatrix}$.
Here, $ a_{23}=9$
and $ a_{24}=6$
$\therefore a_{23}+a_{24}=15$
Also, 15 lies in $3^{\text {id }}$ row and $2^{\text {nd }}$ column.
$\therefore 15=a_{32}$