Question

A constraint in an LP model becomes redundant because:

• A. two iso-profit line may be parallel to each other
• B. the solution is unbounded
• C. this constraint is not satisfied by the solution values
• D. none of the above

Answer 1

Answer: (D)

none of the above

A constraint in an LP model becomes redundant when the feasible region doesn't change by the removing the constraint.

For example, $x+2y\le 20$ and $2x+4y\le 40$ are the constraints.

$2x+4y\le 40⟹2\ast (x+2y)\le 2\ast 20$

$⟹x+2y\le 20$ which is same as the first constraint.

Therefore $2x+4y\le 40$ can be removed. By removing this constraint feasible region doesn't change.