Answer:
13. Invalid. Sure, Cory uses a common person in which to compare too (Jennifer), but if she is shorter than both of them, then it would still not tell him who is taller. He would need to find someone that is as tall as David, and compare that person with himself (or compare directly with David).
14. Invalid. #1, Jennifer finishes her chores by 5 p.m. She does not teleport to the mall (by 5 p.m.), meaning that she is already there then. Unless she does her chores in the mall, it is humanely impossible for this event to occur.
15. Inductive Reasoning. Inductive Reasoning means that you go from a specific event, and generalize it. In this case, it said that "David did not play video games on Wednesday" (A specific date, or a case). Then that case is used to support the generalization of if David does not finish his homework, he does not play video games.
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Note that Deductive Reasoning means that you go from a general premise and narrow it down to a specific event/answer/etc.
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