Answer
Revenue$=\left[\begin{array}{ccc}{15}&{10}&{12}\end{array}\right]\left[\begin{array}{c}{50}\\{40}\\{30}\end{array}\right]$$=[1,510]$
(Total revenue = $\$1,510$)
Work Step by Step
Revenue= Price $\times$ Quantity
Arrange the three prices as a 1$\times$3 row matrix and
the three quantities as a 3$\times$1 column matrix.
These matrices can be multiplied (the resulting matrix is a 1$\times$1 matrix).
Revenue$=\left[\begin{array}{ccc}{15}&{10}&{12}\end{array}\right]\left[\begin{array}{c}{50}\\{40}\\{30}\end{array}\right]$
$=[750+400+360]=[1,510]$
