Question

Suppose P and Q are two different matrices of order 3 × n and n × p , then the order of the matrix P × Q is?
(a) 3 × p (b) p × 3 (c) n × n (d) 3 × 3

Answer 1

Answer: option (a): 3 x p

Explanation:

Given data:

The order of matrix of P = 3 x n

The order of matrix of Q = n x p

To find: The order of matrix P x Q

Solution:

We know that,  

If the columns of the first matrix i.e., “n” from “3 x n” matrix, matches the rows of the second matrix i.e., “n” from “n x p” matrix

Then the “n” being common cancels out and the resultant matrix becomes “3 x p”.

Thus,

The order of matrix “P x Q” is given as,

= [P(₃ ₓ ₙ)] x [Q(ₙ ₓ p)]

= (P x Q)3xp

Answer 2

Answer:

3 X p

Explanation:

in this n gets cancel out and then this tis the order