Exercises 40–51 each have several steps leading to a complete solution to a mixture problem. Practice a specific step of the solution algorithm by working out just that step for several problems. The steps are:

  1. Make a mixture chart for the problem.
  2. Using the mixture chart, write the profit formula and the resource- and minimum-constraint inequalities.
  3. Draw the feasible region for those constraints and find the coordinates of the corner points.
  4. Evaluate the profit information at the corner points to determine the production policy that best answers the question.
  5. (Requires technology) Compare your answer with the one you get from running the same problem on a simplex algorithm computer program.

Question 4.76

46. The firm WebsAreUs creates and maintains websites for client companies. There are two types of websites: “Hot” sites change their layout frequently but keep their content for long times; “cool” sites keep their layout for a while but frequently change their content. Maintaining a hot site requires 1.5 hr of layout time and 1 hr for content changes. Maintaining a cool site requires 1 hr of layout time and 2 hr for content changes. Every day, WebsAreUs has 12 hr available for layout changes and 16 hr for content changes. Net profit is $50 for a set of changes on a hot site and $250 for a set of changes on a cool site. To maximize profit, how many of each type of site should WebsAreUs maintain daily? How, if at all, do the maximum profit and optimal policy change if the company must maintain at least two hot and three cool sites daily?