Question

If A is a matrix consisting of 4 rows and 5 columns, what must be the number of columns in the matrix B so that the product BA is defined?

Answer 1

Matrix B must also be 5 columns

Explanation:

For easy multiplication both matrix should have same number of columns

Answer 2

Explanation:

For the product BA to be defined, the number of columns in matrix A must equal the number of rows in matrix B. Since matrix A has 5 columns, matrix B must have 4 rows. Therefore, the number of columns in matrix B must be 4.