ISDS 361B Test 2
Dr. Chen VERSION L1 Spring 2012
INSTRUCTIONS:
1. There are 15 multiple questions on the test. 7 points for each correct answer. Maximum possible score is 105 points. (100 points is considered perfect).
2. Data file (DATA-L1.XLS) is in the LANSCHOOL folder on Desk top
3. Fill in your section number, last name, first name and station number on the STUDENT worksheet of DATA-L1.XLS before you start.
4. Use DATA-L1.XLS as your calculation spreadsheet. You may insert any worksheet as needed. I will collect DATA-L1.XLS at the end of test for reference purpose.
5. Mark your answer on scantron (882) as soon as you finish one problem.
5. Turn in test questions and scantron at the end of test.
6. University policy for academic dishonesty is to be strictly followed.
ACADEMIC DISHONESTY
Academic dishonesty includes such things as cheating, inventing false information or citations, plagiarism, and helping someone else commit an act of academic dishonesty.
SELECT THE BEST ANSWER
1. In a model with two decision variables, the restriction 3X1 + 2X2 £ 6 represents:
a. A straight line.
b. The region of infeasibility.
c. An extreme point.
d. A linear constraint.
e. None of the above.
2. The functional constraints of a linear model with nonnegative variables are 3X1 + 5X2 £ 16 and 4X1 + X2 £ 10. Which of the following points could not be an optimal solution for the model?
a. X1 = 2.5, X2 = 0
b. X1 = 0, X2 = 3.2
c. X1 = 2, X2 = 2.25
d. X1 = 2, X2 = 2
e. None of the above
3. The principle of “complementary slackness of Objective Function Coefficients ” implies that:
a. If the reduced cost is not zero, than the value of the decision variable is zero.
b. If a decision variable is zero, then its reduced cost must be positive.
c. If a decision variable is zero, then its reduced cost must be negative.
d. If a decision variable is zero, then its reduced cost must be zero.
e. None of the above.
4. It takes 2 pounds of steel and 3 pounds of copper to make one unit of product 1 and 1 pound of steel and 4 pounds of copper to make one unit of product 2. X1 and X2 denote the amount of each product. If there are 100 pounds of steel and 150 pounds of cooper available, one constraint will be
a. 3X1 + 7X2 £ 250
b. 2X1 + X2 £ 100
c. X1 + X2 £ 150
d. X1 + X2 £ 100
e. None of the above
{Problem 5-10} Howard Manufacturing produces five major appliances – stove, washers, electric dryers, gas dryer, and refrigerators. All products go through three processes – molding/pressing, assembly, and packaging.
· Each week there are 5600 minutes available for molding/pressing, 3000 available for packaging, 1200 for stove assembly, 1200 for refrigerator assembly, and 2800 that can be used for assembling washers and dryers.
· The table below gives the gross unit net profit that includes the material and labor as well as the molding/pressing, assembly and packaging times (in minutes) required for the production of each type of appliance:
· Howard will like the number of washers to be equal the combined number of dryers.
· The number of electric dryers should not exceed the number of gas dryers by more than 100 per week
A Linear Programming model is formulated as follows:
Below is the sensitivity report of the Solver solution: (See Worksheet 6)
5. [Howard Manufacturing] The optimal total profit is:
a. $92,166.67
b. $983.33
c. $972.08
d. $12,505.33
e. None of the above
6. [Howard Manufacturing] Profit of electric dryer should be improved to what level before you will recommend producing it?
a. $90
b. $96.25
c. $100
d. $110.25
e. None of the above
7. [Howard Manufacturing] Suppose the assembly time for washer and dryer costs you $10 per minute now, how much should Howard be willing to pay for an extra hour of washer and dryer’s assembly time?
a. $510.5
b. $150
c. $750
d. $165
e. None of the above
8. [Howard Manufacturing] Suppose the molding/pressing time for washer and dryer costs you $12 per minute now, how much should Howard be willing to pay for 100 extra minutes of molding/pressing time?
a. $0
b. $1200
c. $2236
d. $5600
e. None of the above
9. [Howard Manufacturing] Would the optimal production schedule and total profit change if the profit of stove is increased by $10?
a. The optimal production schedule would change, the total profit would not change.
b. The optimal production schedule would not change, the total profit would change.
c. Both the optimal production schedule and the total profit would change.
d. Neither the optimal production schedule nor the total profit would change.
e. None of the above.
10. [Howard Manufacturing] Within what range of values for the net profit of refrigerator’s will the optimal solution remains the same?
a. [30 to 110]
b. [110 to µ]
c. [31 to 133.33]
d. [130 to 133.33]
e. None of the above
11. The critical path:
a. Is the shortest path through the network.
b. Is necessarily unique.
c. Is defined by activities with zero slack.
d. Shows, by elimination, which activities management can safely ignore.
e. None of the above.
12. The probabilistic approach characterized by PERT does not use:
a. Optimistic activity times.
b. Median activity times.
c. Pessimistic activity times.
d. Most likely activity times.
e. None of the above
13. Consider the following network:
a. Earliest Start time of activity E = 8
b. Earliest Start time of activity E = 9
c. Earliest Start time of activity E = 10
d. Earliest Start time of activity E = 12
e. None of the above
[Chocolate Club] The popular recording star Chocolate Club is planning to add a separate recording studio to his palatial complex in rural Connecticut. The blueprints have been completed, and the following table lists the time estimates of the activities in the construction project: (Data is presented in Worksheet 14)
The immediate predecessor relations are listed below which can be copy and paste onto TEMPLATE directly
14. [Chocolate Club] What is the probability that the project will be completed between day 92 and day 99?
f. 0
a. 0.3516
b. 0.5
c. 0.8516
d. None of the above
15. [Chocolate Club] Chocolate Cube has committed himself to a recording session 99 days from now. If his studio is not ready in 99 days, chocolate Club will be forced to lease his record company’s studio which will cost $60,000. For $3,000 extra, the company can accelerate the activity G, each of the three estimates will be reduced by 5 days. Hence, his two options are:
Option 1: Keep the original plan
Option 2: Accelerate activity G
Using the expected cost approach, should the $3,000 be spent to accelerate G? (Skeleton for expected cost analysis is presented in Worksheet 15)
a. NO, G is not a critical activity.
b. YES, G is by all means a critical activity.
c. NO, expected cost of Option 1 is lower.
d. YES, expected cost of Option 2 is lower.
e. None of the above.
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