Question

Which one of the following matrices is singular?

• A. $\left[\begin{array}{cc}2& 5\\ 1& 3\end{array}\right]$
• B. $\left[\begin{array}{cc}3& 2\\ 2& 3\end{array}\right]$
• C. $\left[\begin{array}{cc}2& 4\\ 3& 6\end{array}\right]$
• D. $\left[\begin{array}{cc}4& 3\\ 6& 2\end{array}\right]$

Answer 1

The correct option is C $\left[\begin{array}{cc}2& 4\\ 3& 6\end{array}\right]$

The matrix in option (C) is singular
$\because |A|=\left|\begin{array}{cc}2& 4\\ 3& 6\end{array}\right|=2\times 6-3\times 4=0$