The value of the determinant $\left| \begin{array}{ccc} 2 & 8 & 4 \\ -5 & 6 & -10 \\ 1 & 7 & 2 \end{array} \right|$ is

If the determinant $\left| \begin{array}{ccc} a+p & 1+x & u+f \\ b+q & m+y & v+g \\ c+r & n+z & w+h \end{array} \right|$ splits into exactly $K$ determinants of order $3$,each element of which contains only one term,then the value of $K$ is:

If $\left| \begin{matrix} x - 4 & 2x & 2x \\ 2x & x - 4 & 2x \\ 2x & 2x & x - 4 \end{matrix} \right| = (A + Bx)(x - A)^2$,then the ordered pair $(A, B) = $ . . . . .

Let $P = [a_{ij}]$ be a $3 \times 3$ matrix and let $Q = [b_{ij}]$,where $b_{ij} = 2^{i+j} a_{ij}$ for $1 \leq i, j \leq 3$. If the determinant of $P$ is $2$,then the determinant of the matrix $Q$ is:

If $\begin{vmatrix} ^9C_4 & ^9C_5 & ^{10}C_r \\ ^{10}C_6 & ^{10}C_7 & ^{11}C_{r+2} \\ ^{11}C_8 & ^{11}C_9 & ^{12}C_{r+4} \end{vmatrix} = 0$,then $r$ is equal to:

Consider the following statements :
$(a)$ If any two rows or columns of a determinant are identical,then the value of the determinant is zero.
$(b)$ If the corresponding rows and columns of a determinant are interchanged,then the value of the determinant does not change.
$(c)$ If any two rows (or columns) of a determinant are interchanged,then the value of the determinant changes in sign.
Which of these are correct?