Math Problem Statement

Solve

Solve the following Linear Programming problem using the simplex method. Maximize Z = 6x + 3y, subject to 2x + y ≤ 8, 3x + 3y ≤ 18, y ≤ 3, and x, y ≥ 0.

Solution

Let's solve the Linear Programming problem using the Simplex Method step by step.

Problem:

Maximize Z=6x+3yZ = 6x + 3y

Subject to constraints:

  1. 2x+y82x + y \leq 8
  2. 3x+3y183x + 3y \leq 18
  3. y3y \leq 3
  4. x,y0x, y \geq 0

Step 1: Convert constraints to equalities using slack variables

Introduce slack variables s1,s2,s3s_1, s_2, s_3 for each inequality:

  1. 2x+y+s1=82x + y + s_1 = 8
  2. 3x+3y+s2=183x + 3y + s_2 = 18
  3. y+s3=3y + s_3 = 3

Now, rewrite the objective function and constraints in standard form:

  • Maximize Z=6x+3y+0s1+0s2+0s3Z = 6x + 3y + 0s_1 + 0s_2 + 0s_3
  • Subject to: 2x + y + s_1 &= 8 \\ 3x + 3y + s_2 &= 18 \\ y + s_3 &= 3 \\ x, y, s_1, s_2, s_3 &\geq 0 \end{aligned}$$

Step 2: Initial Simplex Table

The initial simplex table is as follows:

Basisxxyys1s_1s2s_2s3s_3RHS
s1s_1211008
s2s_23301018
s3s_3010013
Z-6-30000

Step 3: Simplex Iteration 1

Step 3.1: Identify entering and leaving variables

  • Entering variable: The column with the most negative value in the bottom row of the objective function. Here, xx (6-6) is the entering variable.
  • Leaving variable: Determine the row using the minimum ratio test: RHS/Pivot column\text{RHS} / \text{Pivot column}. Ratios: 82=4,183=6,30=\text{Ratios: } \frac{8}{2} = 4, \frac{18}{3} = 6, \frac{3}{0} = \infty
    • The minimum ratio is 4 (row 1), so s1s_1 is the leaving variable.

Step 3.2: Perform row operations to make the pivot element 1

  • Pivot element: 22 (row 1, column 1).

Divide row 1 by 2: R1=R1/2New row 1: [1,0.5,0.5,0,0,4]R1 = R1 / 2 \quad \Rightarrow \quad \text{New row 1: } [1, 0.5, 0.5, 0, 0, 4]

Perform row operations on the other rows to make the pivot column 0: R2=R23R1,R3=R30R1,Z=Z+6R1R2 = R2 - 3 \cdot R1, \quad R3 = R3 - 0 \cdot R1, \quad Z = Z + 6 \cdot R1

New tableau:

Basisxxyys1s_1s2s_2s3s_3RHS
xx10.50.5004
s2s_201.5-1.5106
s3s_3010013
Z0030024

Step 4: Simplex Iteration 2

Step 4.1: Identify entering and leaving variables

  • Entering variable: yy (0.50.5 in row 1).
  • Leaving variable: Perform the ratio test. After adjustments, we find yy will continue improving the solution.

At this stage, we see that the iterations stabilize.


Final Solution:

  • x=4x = 4, y=0y = 0
  • Maximum Z=24Z = 24

Would you like more details or want to discuss a specific step?


Related Questions:

  1. What is the geometric interpretation of the Simplex Method?
  2. How do slack variables help in converting inequalities into equalities?
  3. Can you describe the two-phase simplex method?
  4. What is the difference between primal and dual linear programming?
  5. What are some real-world applications of linear programming?

Tip: Always perform the minimum ratio test carefully to avoid errors in identifying the leaving variable.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Linear Programming
Optimization
Simplex Method

Formulas

Objective function: Z = 6x + 3y
Slack variables for constraints

Theorems

Simplex Method
Linear Programming duality principle

Suitable Grade Level

Undergraduate level