IE 3115 Final Exam

Which of the following information on a sensitivity analysis report indicates that alternate optimal solutions exist?

No 0 in the allowable increase and decrease of the constraints table and a 0 in the allowable increase and decrease of the decision variables table

Defining a 5% tolerance in Solver's Integer Optimality option means that

Solver will return a solution that is at least 95% as good as the optimal solution to the original ILP's relaxation problem.

When do alternate optimal solutions occur in LP models?

When a constraint is parallel to a level curve

Which of the following constraints models this condition: "No more than 2 projects can be chosen from the available 4?"

X1+X2+X3+X4<=2

The optimal relaxed solution for an ILP is X1=2.6 and X2=4.1. Which of the following constraints are correct to create the sub problems using the branch and bound algorithm?

X2<=4, X2>=5

Which of the following constraints models this condition: "Road 4 cannot be built unless road 1,2, or 3 is built?"

X4<=X1+X2+X3

Level curve is

associated with the objective function of an LP model

In a maximization ILP problem, the optimal solutions to its ILP relaxation sub problem III is: X1=3, X2=4, Z=8.6,; and sub problem IV is: X1=6.3, X2=4.5, Z=15.3. What is the next step?

branch on sub problem IV

The constraint that has zero shadow price

can be a redundant constraint

Maximal flow problems are converted to transshipment problems by

connecting the supply and demand nodes with a return arc

If there is no way to simultaneously satisfy all the constraints in an LP model the problem is said to be

infeasible

When the feasible region of an LP model becomes a line, it indicates that

one of the constraints is an equation

Why is it desired to have a network flow model's constraints follow the balance of flow rule?

to guarantee integer solutions without adding integer constraints

How many balance-of-flow rule constraints should a network flow problem have if the network has 7 nodes and 12 arcs?

19

A company only accepts orders larger than 250. Which of the following constraints enforce this condition (M is a big numeric value in the constraints)?

250Y1<=X1<=MY1

The constraint X13+X23-X34>=50 for a network flow problem indicates that

50 units are required at node 3