Chapter 9.3, Problem 73PE

An electronics store sells three models of tablets. The number of each model sold during "Black Friday" weekend is given in matrix $A$ . The selling price and profit for each model are given in matrix $B$ . (See Example 8)

$\begin{array}{l}\text{ Model}\\ \begin{array}{ccc}A& B& C\end{array}\\ A=\left[\begin{array}{ccc}84& 70& 32\\ 62& 48& 16\\ 70& 40& 12\end{array}\right]\begin{array}{c}\text{Friday}\\ \text{Saturday}\\ \text{Sunday}\end{array}\end{array}$ $\begin{array}{l}\text{ Selling}\\ \begin{array}{cc}\text{Price}& \text{Profit}\end{array}\\ B=\left[\begin{array}{rr}\hfill \text{\$499}& \hfill \text{\$200}\\ \hfill \text{\$599}& \hfill \text{\$240}\\ \hfill \text{\$629}& \hfill \text{\$280}\end{array}\right]\begin{array}{l}\text{A}\hfill \\ \text{B Model}\hfill \\ \text{C}\hfill \end{array}\end{array}$

a. Compute $AB$ and interpret the result.

b. Determine the total revenue for Sunday.

c. Determine the total profit for the $3$ -day period for these three models.