Answer:
Correct statement: a. x₁ + x₂ + x₃ > 2
Step-by-step explanation:
The variables <em>x</em>₁, <em>x</em>₂ and <em>x</em>₃ takes value 0 if the projects are not done and 1 if the projects are done.
Consider that at least two projects are done, i.e. 2 or more projects are done.
This can happen in:
x₁ = 0, x₂ = 1 and x₃ = 1
x₁ = 1, x₂ = 0 and x₃ = 1
x₁ = 1, x₂ = 1 and x₃ = 0
x₁ = 1, x₂ = 1 and x₃ = 1
The statement (x₁ + x₂ + x₃ > 2) will be true only when all the variables takes the value 1.
This statement implies that 2 projects are definitely done.
Thus, the correct statement is (a).
