CBSE 2025 · Region 4 · Set 1 · Q21 · 2 marks
Let A and B be two square matrices of order $\displaystyle 3$ such that $\displaystyle \operatorname{det}(\mathrm{A})=3$ and $\displaystyle \operatorname{det}(B)=-4$. Find the value of $\displaystyle \operatorname{det}(-6 \mathrm{A} B)$.
Marking-scheme solution
\[\begin{aligned}
& |-6 \mathrm{A} B|=(-6)^{3}|\mathrm{A}||B| \\
& =-216 \times 3 \times(-4)=2592
\end{aligned}
\]
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CBSE Class 12 Mathematics past-paper question from the 2025board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.