Let X₁ and X₂ Be 0 - 1 Variables Whose

question 48

Multiple Choice

Let x₁ and x₂ be 0 - 1 variables whose values indicate whether projects 1 and 2 are not done or are done. Which answer below indicates that project 2 can be done only if project 1 is done?

• A) x₁ + x₂ = 1
• B) x₁ + x₂ = 2
• C) x₁ − x₂ ≤ 0
• D) x₁ − x₂ ≥ 0

---

Definitions:

Efficient Level

An optimal point where resources are utilized in the most productive manner without waste, achieving the best outcome.

Positive Externality

A beneficial effect experienced by a third party as a result of an economic transaction or activity between others.

Negative Externality

A cost that affects a party who did not choose to incur that cost, often a byproduct of production or consumption.

Public Good

A good that is non-excludable and non-rivalrous, meaning individuals cannot be effectively excluded from its use and one person's use does not reduce availability to others.