Question 18

Which statement is not true?

a.

Many network problem could generate integer solution without integer constraints

b.

Because of a. we should not include non-negativity constraint in the formulation

c.

Shortest rout problem is a type of network problems

d.

We can use the balance of flow rule to deal with minimization problems

Question 19

Which statement is true?

a.

To formulate shortest route problem, we assign the demand of 1 at origin and destination, and supply of 1 at other nodes

b.

We create a artificial node to make the formulation of maximum flow problem easier

c.

We may use artificial node to balance the number of supply and demand node in the assignment problem

d.

The artificial arc we create in maximum flow problem has cost of infinity

Question 20

Which is true?

a.

A decision variable X₁₂ in a network problem is equal to X₂₁

b.

For minimization problem, if total supply >= total demand, the flow balance constraint is inflow >= outflow

c.

For maximization problem, you can apply balance of flow rule

d.

All the problems can be converted into network problem