Help on a practice question.
Posted: Sat Jun 04, 2011 12:55 am
I dont understand how I have the wrong answer.
Eight fighter pilots flying over the Amazon notice some hostile activity taking place on a sugar planta- tion. To peaceably resolve the conflict, they land their planes and decide that it would be best to send those pilots who would best complement each other as negotiators to talk to the warring parties. The pilots Anna, Ben, Chris, Dana, Evan, Frank, Garry, and Hillary are chosen as negotiators according to the following conditions:
Anna is chosen if Ben is chosen.
If Garry is not chosen, then Anna and Frank are chosen.
Ben and Hillary are chosen if Anna is chosen.
If Frank is not chosen, then Garry is chosen.
If Hillary is not chosen, then Evan is chosen.
If Chris is not chosen, then Dana is not chosen,
and if Dana is not chosen, then Chris is not chosen.
Who could be sent to negotiate alone?
(A) Garry (B) Anna (C) Chris (D) Dana (E) None of the above
Given how the diagram map is (http://gallery.me.com/pedromcorrea#100017)
I choose (A) Gary, for the fact that his appearance doesn't effect anyones, but the book says (E) is the correct answer with the reasoning "If Hillary is not sent, Evan must be sent, which means that Garry cannot be sent alone."
How does this make any sense?
Eight fighter pilots flying over the Amazon notice some hostile activity taking place on a sugar planta- tion. To peaceably resolve the conflict, they land their planes and decide that it would be best to send those pilots who would best complement each other as negotiators to talk to the warring parties. The pilots Anna, Ben, Chris, Dana, Evan, Frank, Garry, and Hillary are chosen as negotiators according to the following conditions:
Anna is chosen if Ben is chosen.
If Garry is not chosen, then Anna and Frank are chosen.
Ben and Hillary are chosen if Anna is chosen.
If Frank is not chosen, then Garry is chosen.
If Hillary is not chosen, then Evan is chosen.
If Chris is not chosen, then Dana is not chosen,
and if Dana is not chosen, then Chris is not chosen.
Who could be sent to negotiate alone?
(A) Garry (B) Anna (C) Chris (D) Dana (E) None of the above
Given how the diagram map is (http://gallery.me.com/pedromcorrea#100017)
I choose (A) Gary, for the fact that his appearance doesn't effect anyones, but the book says (E) is the correct answer with the reasoning "If Hillary is not sent, Evan must be sent, which means that Garry cannot be sent alone."
How does this make any sense?