# Answer True False 2 points Question 2

 Date 11.10.2016 Size 56.37 Kb.

1.                                                              The solution to the LP relaxation of a maximization integer linear program provides an upper bound for the value of the objective function.

True

False

Question 2

1.

A conditional constraint specifies the conditions under which variables are integers or real variables.

True

False

2 points

Question 3

1.

In a mixed integer model, some solution values for decision variables are integer and others are only 0 or 1.

True

False

2 points

Question 4

1.

If we are solving a 0-1 integer programming problem with three decision variables, the constraint x1 + x2 ≤ 1 is a mutually exclusive constraint.

True

False

2 points

Question 5

1.

Rounding non-integer solution values up to the nearest integer value will result in an infeasible solution to an integer linear programming problem.

True

False

2 points

Question 6

1.

In a 0-1 integer programming problem involving a capital budgeting application (where xj = 1, if project j is selected, xj = 0, otherwise) the constraint x1 - x2 ≤ 0 implies that if project 2 is selected, project 1 can not be selected.

True

False

2 points

Question 7

1.

If we are solving a 0-1 integer programming problem, the constraint x1 ≤ x2 is a __________  constraint.

 multiple choice mutually exclusive conditional corequisite

2 points

Question 8

1.

The Wiethoff Company has a contract to produce 10000 garden hoses for a customer. Wiethoff has 4 different machines that can produce this kind of hose. Because these machines are from different manufacturers and use differing technologies, their specifications are not the same. Write the constraint that indicates they can purchase no more than 3 machines.

 Y1 + Y2 + Y3+ Y4 ≤ 3 Y1 + Y2 + Y3+ Y4 = 3 Y1 + Y2 + Y3+ Y4 ≥3 none of the above

2 points

Question 9

1.

If we are solving a 0-1 integer programming problem, the constraint x1 = x2 is a __________ constraint.

 multiple choice mutually exclusive conditional corequisite

2 points

Question 10

1.

The Wiethoff Company has a contract to produce 10000 garden hoses for a customer. Wiethoff has 4 different machines that can produce this kind of hose. Because these machines are from different manufacturers and use differing technologies, their specifications are not the same. Write a constraint to ensure that if machine 4 is used, machine 1 will not be used.

 Y1 + Y4 ≤ 0 Y1 + Y4 = 0 Y1 + Y4 ≤ 1 Y1 + Y4 ≥ 0

2 points

Question 11

1.

In a __________ integer model, some solution values for decision variables are integers and others can be non-integer.

 total 0 - 1 mixed all of the above

2 points

Question 12

1.

You have been asked to select at least 3 out of 7 possible sites for oil exploration. Designate each site as S1, S2, S3, S4, S5, S6, and S7. The restrictions are:
Restriction 1. Evaluating sites S1 and S3 will prevent you from exploring site S7.
Restriction 2. Evaluating sites S2 or
S4 will prevent you from assessing site S5.
Restriction 3. Of all the sites, at least 3 should be assessed.
Assuming that Si is a binary variable, write the constraint(s) for the second restriction

 S2 +S5 ≤ 1 S4 +S5 ≤ 1 S2 +S5 + S4 +S5 ≤ 2 S2 +S5 ≤ 1,  S4 +S5 ≤ 1

2 points

Question 13

1.

Assume that we are using 0-1 integer programming model to solve a capital budgeting problem and xj = 1 if project j is selected and xj = 0, otherwise.
The constraint (x1 + x2 + x3 + x4 ≤ 2) means that __________ out of the 4 projects must be selected.

 exactly 2 at least 2 at most 2 none of the above

2 points

Question 14

1.

The solution to the linear programming relaxation of a minimization problem will always be __________ the value of the integer programming minimization problem.

 greater than or equal to less than or equal to equal to different than

2 points

Question 15

1.

If the solution values of a linear program are rounded in order to obtain an integer solution, the solution is

 always optimal and feasible sometimes optimal and feasible always optimal but not necessarily feasible never optimal and feasible

2 points

Question 16

1.

If we are solving a 0-1 integer programming problem, the constraint x1 + x2 ≤ 1 is a __________ constraint.

 multiple choice mutually exclusive conditional corequisite

2 points

Question 17

1.

Max Z = 5x1 + 6x2
Subject to: 17x1 + 8x2 ≤ 136
3x1 + 4x2 ≤ 36
x1, x2 ≥ 0 and integer
What is the optimal solution?

 x1 = 6, x2 = 4, Z = 54 x1 = 3, x2 = 6, Z = 51 x1 = 2, x2 = 6, Z = 46 x1 = 4, x2 = 6, Z = 56

2 points

Question 18

1.

In a capital budgeting problem, if either project 1 or project 2 is selected, then project 5 cannot be selected. Which of the alternatives listed below correctly models this situation?

 x1 + x2 + x5 ≤ 1 x1 + x2 + x5 ≥1 x1 + x5 ≤ 1,  x2 + x5 ≤ 1 x1 - x5 ≤ 1,  x2 - x5 ≤ 1

2 points

Question 19

1.

Max Z =   3x1 + 5x2
Subject to:      7x1 + 12x2 ≤ 136
3x1 + 5x2 ≤ 36
x1, x2 ≥ 0 and integer

Find the optimal solution. What is the value of the objective function at the optimal solution. Note: The answer will be an integer. Please give your answer as an integer without any decimal point. For example, 25.0 (twenty-five) would be written 25

2 points

Question 20

1.

Consider the following integer linear programming problem

Max Z =      3x1 + 2x2
Subject to:   3x1 + 5x2 ≤ 30
5x1 + 2x2 ≤ 28
x1 ≤ 8
x1 ,x2 ≥ 0 and integer

Find the optimal solution. What is the value of the objective function at the optimal solution. Note: The answer will be an integer. Please give your answer as an integer without any decimal point. For example, 25.0 (twenty-five) would be written 25