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Ch6 Simplex-Based Sensitivity Analysis and Duality



Multiple Choice
Identify the choice that best completes the statement or answers the question.
 

 1. 

Dual prices and ranges for objective function coefficients and right-hand side values are found by considering
a.
dual analysis.
b.
optimality analysis.
c.
ranging analysis.
d.
sensitivity analysis.
 

 2. 

For the basic feasible solution to remain optimal
a.
all cj - zj values must remain £ 0.
b.
no objective function coefficients are allowed to change.
c.
the value of the objective function must not change.
d.
each of the above is true.
 

 3. 

A one-sided range of optimality
a.
always occurs for non-basic variables.
b.
always occurs for basic variables.
c.
indicates changes in more than one coefficient.
d.
indicates changes in a slack variable's coefficient.
 

 4. 

A linear programming problem with the objective function 3x1 + 8x2 has the optimal solution x1 = 5, x2 = 6. If c2 decreases by 2 and the range of optimality shows 5 £ c2 £ 12, the value of Z
a.
will decrease by 12.
b.
will decrease by 2.
c.
will not change.
d.
cannot be determined from this information.
 

 5. 

The improvement in the value of the optimal solution per-unit increase in a constraint's right-hand side is
a.
the slack value.
b.
the dual price.
c.
never negative.
d.
the 100% rule.
 

 6. 

The dual variable represents
a.
the marginal value of the constraint
b.
the right-hand side value of the constraint
c.
the artificial variable
d.
the technical coefficient of the constraint
 

 7. 

The range of feasibility indicates right-hand side values for which
a.
the value of the objective function will not change.
b.
the values of the decision variables will not change.
c.
those variables which are in the basis will not change.
d.
more simplex iterations must be performed.
 

 8. 

If the dual price for b1 is 2.7, the range of feasibility is 20 £ b1 £ 50, and the original value of b1 was 30, which of the following is true?
a.
There currently is no slack in the first constraint.
b.
We would be willing to pay up to €2.70 per unit for up to 20 more units of resource 1.
c.
If only 25 units of resource 1 were available, profit would drop by €13.50.
d.
Each of the above is true.
 

 9. 

The number of constraints to the dual of the following problem is:

Max Z= 3x1 + 2x2 + 6x3
  
s.t.4x1 + 2x2 + 3x3  ³  100
 2x1 + x2 - 2x3  £  200
 4x2 + x3  ³  200
a.
1.
b.
2.
c.
3.
d.
4.
 

 10. 

Given the simplex tableau for the optimal primal solution
a.
the values of the dual variables can be found from the cj - zj values of the slack/surplus variable columns.
b.
the values of the dual surplus variables can be found from the cj - zj values of the primal decision variable columns.
c.
the value of the dual objective function will be the same as the objective function value for the primal problem.
d.
each of the above is true.
 



 
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