To solve this problem, we need to formulate a linear programming (LP) model. Let's denote:

• $x_1$ as the amount of milk (in gallons) bought from Dairy I.
• $x_2$ as the amount of milk (in gallons) bought from Dairy II.

The goal is to maximize the amount of butterfat, subject to constraints related to the total amount of milk bought.

Step 1: Objective function (maximize butterfat)

Let’s assume the butterfat content of milk from Dairy I is $b_1$ gallons of butterfat per gallon of milk, and from Dairy II is $b_2$ gallons of butterfat per gallon of milk. The total amount of butterfat is:

$\text{Maximize butterfat} = b_1 \cdot x_1 + b_2 \cdot x_2$

Step 2: Constraints

1. The total milk purchased should not exceed 100 gallons: $x_1 + x_2 \leq 100$
2. Non-negativity constraints: $x_1 \geq 0, \quad x_2 \geq 0$

Step 3: Additional Data

To proceed further, we need to know the values of $b_1$ and $b_2$, i.e., the butterfat content of the milk from Dairy I and Dairy II. With these values, we can solve for the optimal quantities $x_1$ and $x_2$ and determine the maximum amount of butterfat.

Please provide the butterfat content for each dairy (or any additional constraints), and I can complete the solution for you!

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Let me know if you need further details, or if you have additional questions. Here are five questions that might help you think through the problem:

1. What are the butterfat contents of milk from Dairy I and Dairy II?
2. Are there minimum milk requirements for each dairy?
3. Can the company buy exactly 100 gallons, or does it have to be less than or equal to 100?
4. What are the prices for milk from each supplier, if cost is also a factor?
5. Should the solution account for transportation or other logistics costs?

Tip: When solving optimization problems, always ensure that you have the correct objective and all constraints clearly defined before solving!