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CBSE Class 12 Math 2020 Delhi Set 1 Solved Paper

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Section-A
Question numbers 1\mathbf{1} to 10\mathbf{10} are multiple choice questions. Select the correct option :
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Question : 1 of 36
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If AA is a square matrix of order 3,such3, \text{such} that A(adj⁡A)=10IA(\operatorname{adj} A)=10I, then ∣adj⁡A∣|\operatorname{adj} A| is equal to
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∵A(adj⁡⋅A)=∣A∣I\because A(\operatorname{adj} \cdot A)=|A|I
∴∣A∣=10\therefore |A|=10
So, ∣adj⁡⋅A∣=∣A∣3−1=102=100|\operatorname{adj} \cdot A|=|A|^{3-1}=10^2=100.
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