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If $A$ and $B$ are square matrices of the same order $3$, such that $|A| = 2$ and $AB = 2I$, write the value of $|B|$. |
1 2 3 4 |
4 |
The correct answer is Option (4) → 4 ## $AB = 2I$ $\Rightarrow |AB| = |2I|$ $\Rightarrow |A| \cdot |B| = 2^3|I|$ $\Rightarrow 2 \times |B| = 8$ $\Rightarrow |B| = 4$ |
