Marcel is purchasing a board to build a bookcase. he wants to divide the board into 1.75-foot sections. he needs 6 sections. what size board does marcel need?

solution:

→c= a b , that is product of a and b is possible only when when a is m × n matrix and b is n × p matrix.

that is, number of columns of a= number of rows of b.

so, size of matrix , c= a b is , if a = (m × n)matrix

b= (n × p)matrix

then a b = [ (m × n)matrix] ×[   (n × p)matrix ]

→→c= a b= [m × p ] matrix

→→size of product a b will be equal to = number of rows of a × number of columns of b

x:       y:  

-1         4

0         4

1         6

2         18

3         20