Question

To raise money for an orphanage, students of three schools A, B and C organized an exhibition in their locality, where they sold paper bags, scrap books and pastel sheets made by them using recycled paper at the rate of $\square 20$, $\square 15$, and $\square 10$ per unit respectively. School A sold $25$ paper bags, $10$ scrap books and $30$ pastel-sheets. School B sold $20$ paper bags, $15$ scrap books and $30$ pastel-sheets while School C sold $25$ paper bags, $18$ scrap books and $35$ pastel-sheets. Using matrices, find the total amount raised by each school.

Answer 1

We can form matric of $A,B,C$

$L=\left(\begin{array}{ccc}25& 10& 30\\ 20& 25& 30\\ 25& 28& 35\end{array}\right)$

And cost matrix $X=\left(\begin{array}{c}20\\ 15\\ 30\end{array}\right)$

Then $LX=$ $\left(\begin{array}{ccc}25& 10& 30\\ 20& 25& 30\\ 25& 28& 35\end{array}\right)$$\left(\begin{array}{c}20\\ 15\\ 30\end{array}\right)$$=\left(\begin{array}{c}950\\ 925\\ 1120\end{array}\right)$