 Hello friends, welcome to the session I am Alka. We are going to discuss matrices. Our given question is 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. We have to find the total amount the bookshop will receive from selling all the books using matrix algebra. Let's start with the solution. As we all know that 1 dozen equal to 12 items. Therefore, total number of chemistry books equal to 10 into 12 equal to 120. Total number of physics books equal to 8 into 12 equal to 96. And total number of economics books equal to 10 into 12 equal to 120. The number of books of different subjects are given as a matrix A which is equal to matrix 120, 96 and 120. The selling prices for each type of books is given as matrix B which is 80, 60 and 40. Therefore, total amount received by selling all the books is given by AB which is equal to 120, 96, 120 multiplied by B which is 80, 60 and 40. This is equal to 120 into 80 plus 96 into 60 plus 120 into 40. This is equal to 96 100 plus 5760 plus 4800. This is equal to 20160. Therefore total amount received is rupees 20,160. Hope you understood the solution and enjoyed the session. Goodbye and take care.