If A is a non-null row matrix with 5 columns and B is a non-null column matrix with 5 rows, how many rows are there in A `xx` B ?

Options

A. 1
B. 5
C. 10
D. 25

Answer

A

Explanation

If there is matrix of m rows and n columns and another with n rows and k columns, their product will be a matrix of m rows and k column.
A is a non-null matrix with one row and 5 columns and B is non-null matrix with 5 rows and one column. Therefore number of row in A `xx` B is 1.