# CBSE 12th Mathematics Board Exam 2020: Important Questions & Answers from Chapter 3 - Matrices

Check important questions and answers for Class 12th Mathematics Board Examination 2020 from Chapter 3 - Matrices.

*Matrices*

The students who will be appearing for CBSE Class 12th Mathematics Examination 2020 on March 17, 2020, can go through the below-mentioned important questions for Chapter 3- Matrices. These Questions are based on the latest syllabus prescribed by the CBSE Board.

**Question 1-** If a matrix has 28 elements, what are the possible orders it can have? What if it has 13 elements?

**Answer: **If the matrix has 28 elements then, the possible orders are given by

1 x 28, 2 x 14, 4 x 7, 7 x 4, 14 x 2, 28 x 1

If it has 13 elements then, the possible orders are 1 x 13 and 13 x 1.

**Question 2- **Construct a2 x 2 matrix, where:

(i)a_{ij} = (i-2j)^{2} / 2 (ii) a_{ij} = |-2i+3j|

**Answer:**

(i)

(ii)

**Question 3- **Find the values of a and b, if A = B, where

**Answer:** The value of a = 2 and b = 2.

**Question 4-** If possible, find the sum of the matrices A and B, where

**Answer: **Here, A and B are of different orders. We know that the addition of two matrices A and B is possible only if the order of both the matrices A and B should be the same.

Hence, the sum of matrices A and B is not possible.

**Question 5-** Find the non-zero value of x satisfying the matrix equation

**Answer: **The non-zero value of x satisfying the matrix equation is 4.

**Question 6-** Find the matrix A satisfying the matrix equation given below:

**Answer: **The matrix A will be:

**Question 7-** Find x, y and z, if the below-mentioned matrix, satisfies A’ = A^{-1 }

**Answer:**

**Question 8-** Express the given matrix as the sum of a symmetric and a skew-symmetric matrix.

**Answer: **

**Question 9-** If possible, using elementary row transformations, find the inverse of the following matrices.

**Answer:** (i)

(ii) The second row of matrix *A* on LHS contains all zeroes, so, the inverse of matrix *A *does not exist.

(iii)

**Question 10-** Find a matrix C such that 3A + 5B + 2C is a null matrix, where:

**Answer:**

**The students will find the above-mentioned questions helpful for the last minute preparation for CBSE Class 12th Mathematics Examination 2020. These important questions are based on the NCERT textbook, previous year papers and sample papers. The students can also check the links mentioned below:**

**CBSE 12th Maths Board Exam 2020: Important Multiple Choice Questions (MCQs) with Answers**

**CBSE 12th Maths Board Exam 2020: Chapter-wise Important Questions & Answers**

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