Question

A dietician is planning a snack package of fruit and nuts. Each ounce of fruit will supply zero units of​ protein, 3 units of​ carbohydrates, and 2 unit of​ fat, and will contain 40 calories. Each ounce of nuts will supply 4 units of​ protein, 2 unit of carbohydrate​, and 4 units of​ fat, and will contain 50 calories. Every package must provide at least 4 units of​ protein, at least 11 units of​ carbohydrates, and no more than 16 units of fat. Find the number of ounces of fruit and number of ounces of nuts that will meet the requirement with the least number of calories. What is the least number of​ calories?

Let x be the ounces of fruit and y be the ounces of nuts. What is the objective function that must by​ minimized?

z = __x + __y

The dietician should use ___ ounce(s) of fruit and ___ ​ounce(s) of nuts. These amounts will have a total of ___calories.
(Type your answer in whole numbers)

Answer 1

Explanation:

Let's assume we need x ounces of fruit and y ounces of nuts to meet the requirements with the least number of calories. Then, the problem can be expressed as an optimization problem:

Minimize: 40x + 50y (since we want to minimize the number of calories) Subject to:

0x + 4y ≥ 4 (we need at least 4 units of protein)3x + 2y ≥ 11 (we need at least 11 units of carbohydrates)2x + 4y ≤ 16 (we cannot have more than 16 units of fat)

To solve this problem, we can use the simplex method. First, we convert the problem to standard form by introducing slack variables:

Minimize: 40x + 50y Subject to:

0x + 4y + s1 = 43x + 2y + s2 = 112x + 4y + s3 = 16

Now we can create the initial simplex tableau:

xys1s2s3RHSs1041004s23201011s32400116z-40-500000

We want to find the minimum value of z, so we need to choose the variable with the most negative coefficient in the bottom row as the entering variable. In this case, that is y. We then choose the variable with the smallest non-negative ratio between the right-hand side and the coefficient of the entering variable in its row as the leaving variable. In this case, that is s3, since 16/4 = 4 is the smallest non-negative ratio.

We then perform the pivot operation to eliminate the coefficient of y in the other rows:

x y s1s2s3RHSs1001-214y3/2101/2-1/24s2-1001-1/25z-100025-15200

We repeat this process until all the coefficients in the bottom row are non-negative. The final tableau is:

x

Answer 2

The objective function that must be minimized is:

z = 40x + 50y

subject to the constraints:

0x + 4y ≥ 4 (protein constraint)

3x + 2y ≥ 11 (carbohydrate constraint)

2x + 4y ≤ 16 (fat constraint)

We want to find the number of ounces of fruit (x) and nuts (y) that will meet the requirement with the least number of calories.

Solving the system of inequalities, we get:

x = 2 ounces

y = 2 ounces

Therefore, the dietician should use 2 ounces of fruit and 2 ounces of nuts. These amounts will have a total of 180 calories (402 + 502).