(a) Matrix for the products $\mathrm{x}, \mathrm{y}, \mathrm{z}$ is
Matrix corresponding to sale price of each product
$\therefore$ The revenue collected by market is given by
$$
\left[\begin{array}{ccc}
10,000 & 2,000 & 18,000 \\
6,000 & 20,000 & 8,000
\end{array}\right]\left[\begin{array}{c}
2 \cdot 50 \\
1.50 \\
1.00
\end{array}\right]=\left[\begin{array}{c}
46,000 \\
53,000
\end{array}\right]
$$
Revenue in each market $₹ 46,000$ and $₹ 53,000$
Total revenue $=₹(46,000+53,000)=₹ 99,000$
(b) The cost price of commodities $\mathrm{x}, \mathrm{y}$ and $\mathrm{z}$ are respectively. ₹ $2.00$, ₹ $1.00$ and $0.50$ cost price of each market is given below.
$$
\begin{aligned}
& {\left[\begin{array}{ccc}
10,000 & 2000 & 18,000 \\
6,000 & 20,000 & 8,000
\end{array}\right]\left[\begin{array}{l}
2 \cdot 00 \\
1 \cdot 00 \\
0 \cdot 50
\end{array}\right] } \\
=& {\left[\begin{array}{crr}
20,000 & 2000 & 9000 \\
12000 & 20000 & 4000
\end{array}\right]=\left[\begin{array}{l}
31,000 \\
36,000
\end{array}\right] } \\
& \text { Total cost price of the commodities each market I } \\
& \text { and II are ₹ } 31,000 \text {, ₹ } 36,000 \\
& \text { Total cost price }=₹ .(31,000+36,000)=₹ 67,000 \\
& \text { Gross profit }=\text { Revenue }-\text { Cost price } \\
&=99,000-67,000=₹ 32,000 .
\end{aligned}
$$