If n = p, then the order of the matrix 7X – 5Z is (A) p x 2 (B) 2 x n (C) n x 3 (D) p x n

Question

If n = p, then the order of the matrix 7X – 5Z is
(A) p x 2
(B) 2 x n
(C) n x 3
(D) p x n

Answer 1

(B) 2 x n

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The order of matrix X is 2 x n.
The order of matrix Z is 2 x p.
7X – 5Z is defined when X and Z are of the same order.
⇒ n-p (given)
Thus, the order of Z is also 2 x n.
Hence, order of 7X – 5Z is 2 x n.