MATH 1324 SEC 0090 Business Mathematics SII
Instructor: Liv Tantalo
Date: 07/21
Test: Exam Chapter 2
Question 8 of 12
Total points: 12
This question: 1 point

Four departments of a company need to order the following amounts of the same products.

\begin{tabular}{|c|c|c|c|c|c|}
\hline
Department & Paper & Tape & Binders & Memo & Pens \\
\hline
1 & 8 & 5 & 4 & 3 & 6 \\
\hline
2 & 6 & 3 & 3 & 2 & 9 \\
\hline
3 & 4 & 7 & 1 & 0 & 10 \\
\hline
4 & 0 & 3 & 6 & 6 & 6 \\
\hline
\end{tabular}

The unit price (in dollars) of each product is given below for two suppliers.

\begin{tabular}{|l|c|c|}
\hline
& Supplier A & Supplier B \\
\hline
Paper & 2 & 3 \\
\hline
Tape & 1 & 1 \\
\hline
Binders & 5 & 3 \\
\hline
Memo & 3 & 3 \\
\hline
Pads & 3 & 1 \\
\hline
Pens & 1 & 1 \\
\hline
\end{tabular}

(a) Use matrix multiplication to get a matrix showing the comparative costs for each department's products from the two suppliers.

(b) Find the total cost over all departments to buy products from each supplier. From which supplier should the company make the purchase?

A. The total cost for Supplier A is \[tex]$ \_\_\_\_\_\_ and the total cost for Supplier B is \$[/tex] \_\_\_\_\_\_. The company should make the purchase from Supplier B.

B. The total cost for Supplier A is \[tex]$ \_\_\_\_\_\_ and the total cost for Supplier B is \$[/tex] \_\_\_\_\_\_. The company should make the purchase from Supplier A.



Answer :

Let's solve this problem step by step:

### Step 1: Represent the quantities ordered by each department in matrix form

Each row of the matrix corresponds to a department, and each column corresponds to a product.

[tex]\[ \text{Quantity Matrix} = \begin{bmatrix} 8 & 5 & 4 & 3 & 6 \\ 6 & 3 & 3 & 2 & 9 \\ 4 & 7 & 1 & 0 & 10 \\ 0 & 3 & 6 & 6 & 6 \end{bmatrix} \][/tex]

### Step 2: Represent the prices from two suppliers

The prices from both suppliers for the ordered products:
[tex]\[ \text{Price from Supplier A} = [2, 1, 5, 3, 1] \][/tex]
[tex]\[ \text{Price from Supplier B} = [3, 1, 3, 3, 1] \][/tex]

### Step 3: Calculate the cost for each department from each supplier

We need to multiply the quantity matrix by the price vectors to get the cost for each department.

For Supplier A:
[tex]\[ \text{Cost}_{A} = \text{Quantity Matrix} \times \text{Price from Supplier A} \][/tex]
[tex]\[ = \begin{bmatrix} 8 & 5 & 4 & 3 & 6 \\ 6 & 3 & 3 & 2 & 9 \\ 4 & 7 & 1 & 0 & 10 \\ 0 & 3 & 6 & 6 & 6 \end{bmatrix} \times \begin{bmatrix} 2 \\ 1 \\ 5 \\ 3 \\ 1 \end{bmatrix} \][/tex]

The result from doing this operation is:
[tex]\[ \text{Cost}_A = [56, 45, 30, 57] \][/tex]

For Supplier B:
[tex]\[ \text{Cost}_{B} = \text{Quantity Matrix} \times \text{Price from Supplier B} \][/tex]
[tex]\[ = \begin{bmatrix} 8 & 5 & 4 & 3 & 6 \\ 6 & 3 & 3 & 2 & 9 \\ 4 & 7 & 1 & 0 & 10 \\ 0 & 3 & 6 & 6 & 6 \end{bmatrix} \times \begin{bmatrix} 3 \\ 1 \\ 3 \\ 3 \\ 1 \end{bmatrix} \][/tex]

The result from doing this operation is:
[tex]\[ \text{Cost}_B = [56, 45, 32, 45] \][/tex]

### Step 4: Calculate the total cost for all departments from each supplier.

Adding the costs for each department for Supplier A:
[tex]\[ \text{Total Cost}_A = 56 + 45 + 30 + 57 = 188 \][/tex]

Adding the costs for each department for Supplier B:
[tex]\[ \text{Total Cost}_B = 56 + 45 + 32 + 45 = 178 \][/tex]

### Step 5: Determine which supplier the company should purchase from

Since the total cost from Supplier B (178) is less than the total cost from Supplier A (188), the company should make the purchase from Supplier B.

### Final Answer:

- Supplier A Total Cost: [tex]\( \$188 \)[/tex]
- Supplier B Total Cost: [tex]\( \$178 \)[/tex]

The company should make the purchase from Supplier B.