NCERT Solutions for Class 12 Maths Chapter 3 Exercise 3.4 Matrices in * Hindi Medium* and

*free to download or use online with download. All solutions are based on new CBSE Curriculum 2018-2019 for CBSE and UP Board students following*

**English Medium****NCERT Books**. Download (

**Exercise 3.4**&

**प्रश्नावली 3.4**) here in PDF or use online solutions given below.

## NCERT Solutions for Class 12 Maths Chapter 3 Exercise 3.4

### Class 12 Maths Chapter 3 Exercise 3.4 Matrices in English

NCERT Solutions for Class 12 Maths Chapter 3 Exercise 3.4 Matrices in English Medium update for the current academic session 2018-19 for UP Board and CBSE Board students. Get here all the exercises of **Class 12 Mathematics Chapter 3**, If you need Solutions in Hindi, CLICK HERE for * Hindi Medium* Solutions.

### Class 12 Maths Chapter 3 Exercise 3.4 Matrices in Hindi

NCERT Solutions for Class 12 Maths Chapter 3 Exercise 3.4 Matrices in Hindi Medium online digital contents as well as downloadable form files. Get here all the exercises of **Class 12 Mathematics Chapter 3**, Go back to * English Medium* Solutions.

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*Solutions.*

**Hindi Medium**#### Important Extra Questions with Answers for Practice

- A matrix X has a + b rows and a + 2 columns while the matrix Y has b + 1 rows and a + 3 columns. Both matrices XY and YX exist. Find a and b. Can you say XY and YX are of the same type? Are they equal. [Answer: a = 2, b = 3, No]
- Prove that the diagonal elements of a skew-symmetric matrix are all zero.
- Give examples of matrices (i) A and B such that AB ≠ BA. (ii) A and B such that AB = O but A ≠ O, B ≠ O. (iii) A and B such that AB = O but BA ≠ O. (iv) A, B and C such that AB = AC but B ≠ C, A ≠ O.
- If A and B are skew symmetric matrices of the same order, prove that AB + BA is symmetric matrix.
- Let A and B be square matrices of the same order. Does (A + B)² = A² + 2AB + B² hold? If not, why?
- The monthly incomes of Mohan and Sohan are in the ratio 3:4 and their monthly expenditures are in the ratio 5:7. If each saves ₹15000 per month, find their monthly incomes and expenditures using matrices. [Answer: ₹90000 and ₹120000]
- For any square matrix write whether AA’ is symmetric of skew-symmetric.
- Three shopkeepers A, B and C go to a store to buy stationary. A purchase 12 dozen notebooks, 5 dozen pens and 6 dozen pencils. B purchases 10 dozen notebooks, 6 dozen pens and 7 dozen pencils. C purchases 11 dozen notebooks, 13 dozen pens and 8 dozen pencils. A notebook costs 40 paise, a pen costs ₹1.25 and a pencil costs 35 paise. Use matrix multiplication to calculate each individual’s bill. [Answer: ₹157.80, ₹167.40 and ₹281.40]