CBSE Class 12 Sample Paper for 2022 Boards (MCQ Based - for Term 1)

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Question 17 - CBSE Class 12 Sample Paper for 2022 Boards (MCQ Based - for Term 1) - Solutions of Sample Papers and Past Year Papers - for Class 12 Boards

Last updated at July 25, 2026 by

Given that A = [š‘Žš‘–š‘—] is a square matrix of order 3 × 3 and |A| = −7, then the value of ∑_(i=1) 3 a i2 A i2 "  , where š“ š‘–š‘— denotes the cofactor of element š‘Žš‘–š‘—  is:

(a) 7  (b) −7  (c) 0  (d) 49

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Question 17 Given that A = [š‘Žš‘–š‘—] is a square matrix of order 3 Ɨ 3 and |A| = āˆ’7, then the value of āˆ‘_(š‘–=1)^3ā–’"š‘Žš‘–2š“š‘–2 " , where š“š‘–š‘— denotes the cofactor of element š‘Žš‘–š‘— is: (a) 7 (b) āˆ’7 (c) 0 (d) 49 Now, = š’‚_šŸšŸ š‘Ø_šŸšŸ+š’‚_šŸšŸ š‘Ø_šŸšŸ+š’‚_šŸšŸ š‘Ø_šŸšŸ = Sum of product of elements of Row R2 with its corresponding cofactors = Determinant of A = |A| = 7 So, the correct answer is (B)

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