QUESTION 12 When we obtain multiple optimal solutions for an LP problem using the simplex method We have zero(s) in z row for some of basic variables in the simplex table We have number of non-basic variables less than the number of zeros in c-z row O We have number of Zeros in c-z greater than the number of the decision variables We have number of constraints less than the number of zeros in c-z row QUESTION 20 In a minimization problem a negative shadow price for a constraint means O the objective function value will decrease, as the right-hand side increases. the objective function value will increase, as the right-hand side decreases the objective function value will increase as the right-hand side increases. the objective function value will decrease, as the right-hand side decreases. QUESTION 21 Artificial variables are added in a constraint when: A readily available basic feasible solution is not available A readily available feasible solution is available. A readily available feasible solution is not available. A readily available basic feasible solution is available