The University Is Scheduling Cleaning Crews for Its Ten Buildings $$x _ { j } = \left\{ \begin{array} { l } 1 , \text { if crew } j \text { is selected } \\0 , \text { otherwise }\end{array} \right.$$

question 74

Multiple Choice

The university is scheduling cleaning crews for its ten buildings. Each crew has a different cost and is qualified to clean only certain buildings. There are eight possible crews to choose from in this case. The goal is to minimize costs while making sure that each building is cleaned. The management science department formulated the following linear programming model to help with the selection process.
Min 200x1 + 250x2 + 225x3 + 190x4 +215x 5 + 245x6 + 235x7 + 220x8
s.t. x1 + x2 + x5 + x7 ? 1 {Building A constraint}
X1 + x2 + x3 ? 1 {Building B constraint}
X6 + x8 ? 1 {Building C constraint}
X1 + x4 + x7 ? 1 {Building D constraint}
X2 + x7 ? 1 {Building E constraint}
X3 + x8 ? 1 {Building F constraint}
X2 + x5 + x7 ? 1 {Building G constraint}
X1 + x4 + x6 ? 1 {Building H constraint}
X1 + x6 + x8 ? 1 {Building I constraint}
X1 + x2 + x7 ? 1 {Building J constraint} $$x _ { j } = \left\{ \begin{array} { l } 1 , \text { if crew } j \text { is selected } \\0 , \text { otherwise }\end{array} \right.$$
Which of the crews is the least expensive?

• A) Crew 1
• B) Crew 2
• C) Crew 3
• D) Crew 4
• E) Crew 5

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Definitions:

Reality Therapy

A therapeutic approach focusing on addressing present issues and choosing behaviors to solve problems effectively.

Cognitive Restructuring

A psychotherapeutic process of identifying and challenging negative and irrational thoughts, and replacing them with more balanced and positive ones.

Social Interest

An individual's sense of belonging and contribution to the welfare of the community.

Family-systems Approach

A therapeutic model which views problems within the context of the family unit, considering the interactions and relationships within it.