other curtains. Suppose he shows you that curtain two is empty. In
fact, he always shows you an empty curtain. (You know that’s how the
game works, the audience knows it, everybody knows it.) Now you
must decide: do you stick with your original choice, curtain three, or
switch to curtain one? Which action gives you the better chance of
finding the grand prize?
4. A Competitive Decision. Consider the following game involving two
players. The players will alternate choosing the nine integers: 1, 2, 3, 4,
5, 6, 7, 8, 9. If the first player picks 4 (let’s say), the second player can
choose any one of the remaining digits, and so on. The first player that
obtains three digits that add up to exactly 15 wins. For instance, the
first player wins with the digits, 2, 3, 6, and 7 since 2 + 6 + 7 = 15. He
would not win with 6, 7, 8, and 9 since no three of them add up to 15.
Ask for two volunteers to play this game (with the rest of the class free
to kibitz). Questions to think about: How would you play? Is it an
advantage to move first? What well-known game does this number
game resemble?
D. Discussion of Guinea Pig Questions. Though these questions are
deliberately set in non-business situations, almost all have interesting
business counterparts. Question 1 demonstrates marginal analysis.
Questions 2 and 3 involve decisions under uncertainty. Question 4 is a
competitive decision.
1. Siting a Shopping Mall. For discussion, see Instructor’s Manual,
Chapter Two, also the Instructor’s Online Site, Chapter Two.
2. Finding the Best Item. For an arbitrary number of items (not only
three), this is variously called the “secretary problem” (interviewing
and selecting the best secretary), the “hotel problem” (deciding to stop
at one of three hotels situated hours apart along a cross-country route),
or the “art gallery problem” (in the gallery you are allowed to view
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