Jagran Josh Logo
  1. Home
  2. |  
  3. CBSE Board|  

NCERT Solutions for CBSE Class 12 Mathematics ‒ Chapter 3: Matrices (Part VI)

Jul 28, 2017 17:45 IST

    NCERT Solutions for CBSE Class 12 Mathematics ‒ Chapter 3: Matrices (Part V)

    NCERT Solutions for CBSE Class 12th Mathematics, Chapter 3: Matrices are available here. In this article, you will find solutions of exercise 3.2 (from question number 17 to question number 22). These questions are related to operations on Matrices. These questions are also important for Class 12 Maths board exam 2018 and other engineering entrance exams like JEE Mains, JEE Advanced etc.

    NCERT Solutions for CBSE Class 12th Maths, Chapter 3: Matrices (Exercise 3.2) from question number 11 to 16 are given below:

    Question 17:

    NCERT Solutions for CBSE Class 12 Mathematics ‒ Chapter 3: Matrices, Question 17

    Solution 17:

    NCERT Solutions for CBSE Class 12 Mathematics ‒ Chapter 3: Matrices, Solution 17

    Download NCERT Solutions for Class 12 Maths (Chapter 3 - Matrices) in PDF format

    NCERT Exemplar Questions: CBSE Class 12 Mathematics – Chapter 3

    Questtion 18:

    NCERT Solutions for CBSE Class 12 Mathematics ‒ Chapter 3: Matrices, Question 18

    Solution 18:

    NCERT Solutions for CBSE Class 12 Mathematics ‒ Chapter 3: Matrices, Solution 18

    Question 19:

    A trust fund has Rs 30,000 that must be invested in two different types of bonds. The first bond pays 5% interest per year, and the second bond pays 7% interest per year. Using matrix multiplication, determine how to divide Rs 30,000 among the two types of bonds. If the trust fund must obtain an annual total interest of:

    (a) Rs 1800

    (b) Rs 2000

    Solution 19:

    NCERT Solutions for CBSE Class 12 Mathematics ‒ Chapter 3: Matrices, Solution 19

    Question 20: The bookshop of a particular school has 10 dozen chemistry books, 8 dozen physics books, 10 dozen economics books. Their selling prices are Rs 80, Rs 60 and Rs 40 each respectively. Find the total amount the bookshop will receive from selling all the books using matrix algebra.

    Solution 20:

    NCERT Solutions for CBSE Class 12 Mathematics ‒ Chapter 3: Matrices, Solution 20

    Assume X, Y, Z, W and P are matrices of order 2 × n, 3 × k, 2 × p, n × 3 and p × k, respectively. Choose the correct answer in Exercises 21 and 22.

    Question 21: The restriction on n, k and p so that PY + WY will be defined are:

    (A) k = 3, p = n

    (B) k is arbitrary, p = 2

    (C) p is arbitrary, k = 3

    (D) k = 2, p = 3

    Solution 21:

    Order of matrix P = p × k

    Order of matrix Y= 3 × k

    Consequently, PY will be of the order = p × k

    Order of matrix W = n × 3 Order of matrix Y = 3 × k

    Matrix WY is well-defined and is of the order n × k

    Matrices PY and WY can be added only when their orders are the same.

    However,

    Order of PY = p × k Order of WY = n × k

    Therefore, p = n

    Thus, k = 3 and p = n are the restrictions on n, k, and p so that PY + WY will be defined.

    Question 22: If n = p, then the order of the matrix 7X – 5Z is:

    (A) p × 2 (B) 2 × n (C) n × 3 (D) p × n

    Solution 22:

    Order of matrix X = 2 × n

    Therefore, Order of matrix 7X is also of the same order.

    Order of matrix Z = 2 × p, i.e., 2 × n [Since n = p]

    Therefore, Order of matrix 5Z is also of the same order.

    Now, Order of matrices 7X and 5Z = 2 × n

    Thus, Matrix 7X − 5Z is well-defined and is of the order 2 × n.

    The correct answer is B.

    CBSE Classs 12 Previous Year Papers

    DISCLAIMER: JPL and its affiliates shall have no liability for any views, thoughts and comments expressed on this article.

    Latest Videos

    Register to get FREE updates

      All Fields Mandatory
    • (Ex:9123456789)
    • Please Select Your Interest
    • Please specify

    • ajax-loader
    • A verifcation code has been sent to
      your mobile number

      Please enter the verification code below

    Newsletter Signup
    Follow us on
    This website uses cookie or similar technologies, to enhance your browsing experience and provide personalised recommendations. By continuing to use our website, you agree to our Privacy Policy and Cookie Policy. OK
    X

    Register to view Complete PDF