Last updated at May 29, 2018 by Teachoo

Transcript

Ex 3.2, 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. Number of chemistry books = 10 dozen = 10 × 12 = 120 Number of physics books = 8 dozen = 8 × 12 = 96 Number of economics books = 10 dozen = 10 × 12 = 120 Let matrix A denote the number of books per subject. A = [ 120 96 120 ] Let Matrix B denote the selling price of books per subject B = [█(80@60@40)] Now, Total amount the shopkeeper receives = Number of books × Selling price = AB = 〖"[ 120 96 120 ]" 〗_(1 × 3) [■8(80@60@40)]_(3 × 1) = 〖["180 × 80 + 96 × 60 + 120 × 40" ]〗_(1 × 1) = "180 × 80 + 96 × 60 + 120 × 40" = 9600 + 5760 + 4800 = 20160 Hence total amount received by shopkeeper is Rs. 20160

Chapter 3 Class 12 Matrices

Ex 3.1, 7
Important

Ex 3.1, 9 Important

Example 18 Important

Example 19 Important

Ex 3.2, 7 Important

Ex 3.2, 12 Important

Ex 3.2, 16 Important

Ex 3.2, 17 Important

Ex 3.2, 20 Important You are here

Example 22 Important

Ex 3.3, 4 Important

Ex 3.3, 10 Important

Ex 3.3, 12 Important

Ex 3.4, 15 Important

Ex 3.4, 17 Important

Example 28 Important

Misc. 3 Important

Misc. 9 Important

Misc. 11 Important

Misc. 13 Important

Class 12

Important Question for exams Class 12

- Chapter 1 Class 12 Relation and Functions
- Chapter 2 Class 12 Inverse Trigonometric Functions
- Chapter 3 Class 12 Matrices
- Chapter 4 Class 12 Determinants
- Chapter 5 Class 12 Continuity and Differentiability
- Chapter 6 Class 12 Application of Derivatives
- Chapter 7 Class 12 Integrals
- Chapter 8 Class 12 Application of Integrals
- Chapter 9 Class 12 Differential Equations
- Chapter 10 Class 12 Vector Algebra
- Chapter 11 Class 12 Three Dimensional Geometry
- Chapter 12 Class 12 Linear Programming
- Chapter 13 Class 12 Probability

About the Author

Davneet Singh

Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 8 years. He provides courses for Maths and Science at Teachoo. You can check his NCERT Solutions from Class 6 to 12.