For this question, make use of the layout of each table to visualise the resulting matrix. Recall that in matrix multiplication, the number of columns in the first matrix must be equal to the number of rows in the second matrix (see the highlighted portion).

Multiply the elements of the highlighted row with the corresponding elements of the highlighted column, and sum up each product. Your resulting matrix should have the same number of rows as your first matrix, and the same number of columns as your second matrix.

In part (b), sum up the elements in each column and make a comparison.