CBSE 2025 · Region 2 · Set 2 · Q8 · 1 mark
Four friends Abhay, Bina, Chhaya and Devesh were asked to simplify $\displaystyle 4 \mathrm{AB}+3(\mathrm{AB}+\mathrm{BA})-4 \mathrm{BA}$, where A and B are both matrices of order $\displaystyle 2 \times 2$. It is known that $\displaystyle \mathrm{A} \neq \mathrm{B} \neq \mathrm{I}$ and $\displaystyle \mathrm{A}^{-1} \neq \mathrm{B}$. Their answers are given as : Abhay : $\displaystyle 6$ AB Bina: $\displaystyle 7$ AB - BA Chhaya: $\displaystyle 8$ AB Devesh : $\displaystyle 7$ BA - AB Who answered it correctly?
Official answer
From CBSE’s own marking scheme for this paper.
(B)
Bina
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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.