XII Maths Chapter 3. Matrix | Page 10

Price at shop 1 : Eraser 6 , Pencil 7 & Price at shop 2 : eraser 4 , Pencil 6
What will be the cost when Amit & Aditi buys these items from Shop 1 & Shop 2 .
We can represent this data using matrix & use the concept of multiplication of two matrices to find the total price .
Using the Product of Matrices we can say that Amit will have to pay 79 if he buys from shop 1 & 62 if he has to buy from shop 2 . Similarly Aditi has to pay 46 if she buys from shop 1 & 35 if she buys from shop 2 .
The product of two matrices A and B is defined if the number of columns of A is equal to the number of rows of B . Let A = [ aij ] be an m × n matrix and B = [ bjk ] be an n × p matrix . Then the product of the matrices A and B is the matrix C of order m × p . To get the ( i , k ) th element cik of the matrix C , we take the i th row of A and k th column of B , multiply them element wise and take the sum of all these products
Note : If AB is defined , then BA need not be defined For approach to multiplication refer ExamFear video lessons .