In January, the Left Coast Bookstore chain sold 600 hardcover books, 1,100 softcover books, and 1,800 plastic books in San Francisco; it sold 300 hardcover, 100 softcover, and 300 plastic books in Los Angeles. Hardcover books sell for $32 each, softcover books sell for $7 each, and plastic books sell for $11 each. $\begin{array} { | l | l | l | l | }
\hline & \text { Hard } & \text { Soft } & \text { Plastic } \
\hline \text { San Francisco } & 600 & 1,100 & 1,800 \
\hline \text { Los Angeles } & 300 & 100 & 300 \
\hline
\end{array}$ Use matrix multiplication to compute the total revenue at the two stores.

Question

In January, the Left Coast Bookstore chain sold 600 hardcover books, 1,100 softcover books, and 1,800 plastic books in San Francisco; it sold 300 hardcover, 100 softcover, and 300 plastic books in Los Angeles. Hardcover books sell for $32 each, softcover books sell for $7 each, and plastic books sell for $11 each. $\begin{array} { | l | l | l | l | } 
\hline & \text { Hard } & \text { Soft } & \text { Plastic } \
\hline \text { San Francisco } & 600 & 1,100 & 1,800 \
\hline \text { Los Angeles } & 300 & 100 & 300 \
\hline
\end{array}$   Use matrix multiplication to compute the total revenue at the two stores.

Quizplus · Accepted Answer

The revenue for each store is calculated by multiplying the number of each type of book sold by its price and summing the results. For San Francisco: $600 \times 32 + 1100 \times 7 + 1800 \times 11 = 46,700$. For Los Angeles: $300 \times 32 + 100 \times 7 + 300 \times 11 = 13,600$.

In January, the Left Coast Bookstore Chain Sold 600 Hardcover