COB 291 TEST 2 REVIEW QUESTIONS
AND ANSWERS
aij - Correct Answers -Consumption ratio/technical coefficient; the amount of change in
Z value with additional units of corresponding resources
bi - Correct Answers -RHS; Amount of resource required and/or available, depending
upon sign of inequality/if it is an equality constraint
Cj - Correct Answers -Objective function coefficient; the change in Z value with
additional production of corresponding decision variable.
Non-negativity - Correct Answers -one constraint every LP problem has.
Non-negativity and Sum of Decision Variables = 1 - Correct Answers -Constraints
needed when an LP problem has decision variables that represent proportions or
percentages.
Key characteristics of Mixing/Blending Problems - Correct Answers -When writing
objective function/constraints, percentages representing parameters are generally
turned into decimals for purposes of the problem and coming up with an answer that
actually makes sense. Non-negativity and Sumer of Decision Variables = 1 constraints
5 steps to formulating LP models - Correct Answers -- *Understand* the problem.
- Identify the *Decision Variables*
- State the *objective function* as a *linear combination* of *decision variables*
- State the *constraints* as *linear combinations* of *decision variables*
- Identify and *upper or lower boundaries* on the decision variables
Unit contribution - Correct Answers -another name for reduced cost and is calculated
from (choose one: aij, bi, and Cj) Cj-opportunity cost
The opportunity cost is calculated by... - Correct Answers -Multiplying the "new"
product's aij values associated with each constraint by the constraint's shadow price,
then summing the total of these
For a minimization problem... - Correct Answers -we only produce a new item if the
item's unit contribution is negative
Decision variables - Correct Answers -what you as the decision maker has control over
AND ANSWERS
aij - Correct Answers -Consumption ratio/technical coefficient; the amount of change in
Z value with additional units of corresponding resources
bi - Correct Answers -RHS; Amount of resource required and/or available, depending
upon sign of inequality/if it is an equality constraint
Cj - Correct Answers -Objective function coefficient; the change in Z value with
additional production of corresponding decision variable.
Non-negativity - Correct Answers -one constraint every LP problem has.
Non-negativity and Sum of Decision Variables = 1 - Correct Answers -Constraints
needed when an LP problem has decision variables that represent proportions or
percentages.
Key characteristics of Mixing/Blending Problems - Correct Answers -When writing
objective function/constraints, percentages representing parameters are generally
turned into decimals for purposes of the problem and coming up with an answer that
actually makes sense. Non-negativity and Sumer of Decision Variables = 1 constraints
5 steps to formulating LP models - Correct Answers -- *Understand* the problem.
- Identify the *Decision Variables*
- State the *objective function* as a *linear combination* of *decision variables*
- State the *constraints* as *linear combinations* of *decision variables*
- Identify and *upper or lower boundaries* on the decision variables
Unit contribution - Correct Answers -another name for reduced cost and is calculated
from (choose one: aij, bi, and Cj) Cj-opportunity cost
The opportunity cost is calculated by... - Correct Answers -Multiplying the "new"
product's aij values associated with each constraint by the constraint's shadow price,
then summing the total of these
For a minimization problem... - Correct Answers -we only produce a new item if the
item's unit contribution is negative
Decision variables - Correct Answers -what you as the decision maker has control over
