Hi:
We are asking the Practice Exam team in the Certification group to review the questions related to dimensions. They can work with the class instructors to make sure that the Practice Exam is in sync with the class. Without seeing the full question, it's hard to give you a definitive answer.
One of the instructors did comment this about the question on page 2-6:
Maximize 12x + 9y
Subject to x+3y <= 225
x+y <= 117
3x+4y <= 420
x>=0, y>=0
This problem is a 2 dimensional problem since there are 2 decision variables, in this case x and y are the 2 decision variables. So if the Pearson question was EXACTLY the same, then the answer should be 2, as you indicate. This is what the Certification team will have to check with the developers.
Thanks for your patience while we investigate,
Cynthia