Posted by Stacy on Wednesday, September 30, 2009 at 3:24pm.
Consider the set of northwestern states or provinces ( Montana, Washington, Idaho, Oregon ,Alaska, British?
Columbis, Alberta). If a person chooses one element, show that in three yes or no questions, we can determine the element.

math  drwls, Wednesday, September 30, 2009 at 3:31pm
There are seven "elements" in the set.
The first question can help you choose between a subgroup of three or four. In the worst case, you will be left with a subgroup of 4 after the first question. One more question can isolate two, and a third question can isolate one of those two.