- A$\frac{23}{81}$
- B$\frac{22}{81}$
- C$\frac{45}{162}$
- D$\frac{43}{162}$
$\text { Total case }=6^{4}$
For non-singular matrix $|\mathrm{A}| \neq 0 \Rightarrow \mathrm{ad}-\mathrm{bc} \neq 0$ $\Rightarrow \mathrm{ad} \neq \mathrm{bc}$
And $\mathrm{a}, \mathrm{b}, \mathrm{c}, \mathrm{d}$ are all different numbers in the set $\{1,2,3,4,5,6\}$ Now for $\mathrm{ad}=\mathrm{bc}$
$(i)$ $6 \times 1=2 \times 3$
$6 \times 1=6, b=2, c=3, d=1$
$\text { or } a=1, b=2, c=3, d=6$
$8 \text { such cases }$
$(ii)$
$6 \times 2=3 \times 4$
$6 \times=6, b=2, c=3, d=2$
$\text { or } a=1, b=3, c=4, d=6$
$8 \text { such cases }$
favourable cases
$={ }^{6} \mathrm{C}_{4}\lfloor 4-16$
required probability
$=\frac{{ }^{6} \mathrm{C}_{4} \lfloor-16}{6^{4}}=\frac{43}{162}$
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