Set up a system of equations and then solve using inverse matrices.

A manufacturer of portable tools has three sets: Basic, Homeowner, and Pro, which must be painted, assembled, and packaged for shipping. The following table gives the number of hours required for each operation for each set.

\begin{tabular}{|c|c|c|c|}
\hline & Basic & Homeowner & Pro \\
\hline Painting & 1.2 & 2 & 2.9 \\
Assembly & 0.8 & 1.4 & 1.7 \\
Packaging & 0.6 & 0.9 & 1.6 \\
\hline
\end{tabular}

If the manufacturer has 91.4 hours for painting per day, 57.8 hours for assembly per day, and 46.8 hours for packaging per day, how many sets of each type can be produced each day?

The manufacturer can produce [tex]$\square$[/tex] Basic sets, [tex]$\square$[/tex] Homeowner sets, and [tex]$\square$[/tex] Pro sets per day.



Answer :

To solve this problem, we need to set up a system of equations based on the information provided about the hours required for each operation and the total available hours each day.

Let's denote:
- [tex]\( x \)[/tex] as the number of Basic sets produced each day,
- [tex]\( y \)[/tex] as the number of Homeowner sets produced each day,
- [tex]\( z \)[/tex] as the number of Pro sets produced each day.

The given table provides the following information on the hours required for each type of set:

[tex]\[ \begin{array}{|c|c|c|c|} \hline & \text{Basic} & \text{Homeowner} & \text{Pro} \\ \hline \text{Painting} & 1.2 & 2 & 2.9 \\ \text{Assembly} & 0.8 & 1.4 & 1.7 \\ \text{Packaging} & 0.6 & 0.9 & 1.6 \\ \hline \end{array} \][/tex]

Also given are the total hours available for each operation per day:
- 91.4 hours for painting,
- 57.8 hours for assembly,
- 46.8 hours for packaging.

Using this information, we can set up the following system of linear equations:

1. For painting:
[tex]\[ 1.2x + 2y + 2.9z = 91.4 \][/tex]

2. For assembly:
[tex]\[ 0.8x + 1.4y + 1.7z = 57.8 \][/tex]

3. For packaging:
[tex]\[ 0.6x + 0.9y + 1.6z = 46.8 \][/tex]

To find [tex]\( x \)[/tex], [tex]\( y \)[/tex], and [tex]\( z \)[/tex], we can represent this linear system in matrix form [tex]\( A \mathbf{x} = \mathbf{b} \)[/tex], where [tex]\( A \)[/tex] is the coefficient matrix, [tex]\( \mathbf{x} \)[/tex] is the vector of unknowns, and [tex]\( \mathbf{b} \)[/tex] is the vector of the right-hand side constants:

[tex]\[ A = \begin{bmatrix} 1.2 & 2.0 & 2.9 \\ 0.8 & 1.4 & 1.7 \\ 0.6 & 0.9 & 1.6 \end{bmatrix} , \mathbf{x} = \begin{bmatrix} x \\ y \\ z \end{bmatrix} , \mathbf{b} = \begin{bmatrix} 91.4 \\ 57.8 \\ 46.8 \end{bmatrix} \][/tex]

To solve for [tex]\( \mathbf{x} \)[/tex], we can use the inverse of the matrix [tex]\( A \)[/tex], denoted [tex]\( A^{-1} \)[/tex]. The solution is given by:

[tex]\[ \mathbf{x} = A^{-1} \mathbf{b} \][/tex]

The computed solution is:

[tex]\[ \mathbf{x} = \begin{bmatrix} x \\ y \\ z \end{bmatrix} = \begin{bmatrix} 5.999999999999552 \\ 16.00000000000018 \\ 18.000000000000064 \end{bmatrix} \][/tex]

Rounding to the nearest whole number, we find:

[tex]\[ x \approx 6, \quad y \approx 16, \quad z \approx 18 \][/tex]

Therefore, the manufacturer can produce:
- [tex]\( 6 \)[/tex] Basic sets,
- [tex]\( 16 \)[/tex] Homeowner sets,
- [tex]\( 18 \)[/tex] Pro sets per day.