Logical reasoning PrepTest 155 · Section 1 · Question 8

This is a different flaw. Remember, "without" statements require us to negate the sufficient condition, whichever condition we put on the sufficient side. For simplicity's sake, let's put "cannot play the piano well" on the sufficient side and negate it to "play the piano well." That would mean we should diagram this as:

1.  Play Piano Well -> Excellent Ear or Exceptional Dexterity
2. Paul: Play Piano Well
   Conclusion: Paul: Excellent Ear & Exceptional Dexterity

Paul only needs one of those two necessary conditions to play well, but this argument erroneously concludes he has both. That's a flaw, but it's not the same flaw as the one committed in the passage. (Advanced test-takers could eliminate this one as soon as they saw the "or" was in the necessary, not sufficient, condition of the premise.)

Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Flawed Parallel Reasoning

Stimulus Summary:
Someone who doesn't have both a high school diploma and competence in CPR can't become a licensed EMT. Maggie has a high school diploma and competence in CPR, so she will become a licensed EMT.

Strategy Overview:

1. Argument or facts? Always argument, so identify premises and conclusions of argument
2. Diagrammable?
   1. If yes, diagram out premises and conclusion.
   2. Note key identifiable characteristics of argument (How many premises? Quantifiers? Ands/ors? Didn't reverse or negate?). Can also convert specific terms in diagram to As, Bs, Cs, Ds, etc.
      1. Eliminate an answer choice as soon as you notice it doesn't possess a key identifiable characteristic the passage possesses
      2. Diagram remaining until you find a matching flaw
   3. If not, paraphrase what the flaw is
      1. Checking to see if a common logical fallacies is committed is very helpful
      2. Select answer choice that has the same flaw

Answer Anticipation:
This passage is diagrammable, as are about half of all Flawed Parallel Reasoning questions, so we'll start there. Before diagramming the first premise, remember that "not both A and B" should be diagrammed as "NOT A or NOT B"...

1. NOT HS Diploma or NOT Competence in CPR → NOT EMT
2. Maggie: HS DIPLOMA and COMPETENCE IN CPR
   Conclusion: Maggie: EMT

See the flaw? The author believes that not satisfying the sufficient condition means we won't get the necessary condition. In other words, the conditions have been negated but not reversed. The valid contrapositive of the premise would be "EMT -> HS Diploma & Competence in CPR." So Maggie possesses two necessary conditions of becoming an EMT. That doesn't mean she'll become an EMT.

Consider a more straightforward version of this same argument: "If you don't have any lasagna noodles, you can't make lasagna tonight. There are lasagna noodles in my cabinet, so I must be making lasagna tonight." Right? Of course not. Sure, I have one necessary condition to making lasagna, but that doesn't mean I'll make lasagna tonight. What if I don't feel like making lasagna? What if I don't have cheese, or tomato sauce, or an oven?

Likewise, Maggie may (shout out Rod Stewart) have two necessary conditions to becoming an EMT, but what if she doesn't feel like becoming an EMT? What if bodily fluids make her squeamish, or she has a deathly fear of riding in ambulances, or she refuses to wear navy uniforms?

So, we'll be looking for an answer choice that has committed the same flaw: negating a conditional statement without reversing it.

Answer Choice Explanation:
Now, here's a perfect match for the stimulus. You need two necessary conditions (fluency in two languages) to be an effective foreign language teacher. Professor Yessios has that necessary condition (fluency in two languages), so she must be an effective foreign language teacher. For the record, we'd diagram this as:

1. NOT Fluent in 2 Languages -> NOT Effective Foreign Langauge Teacher
2. Professor Yessios: Fluent in 2 Languages
   Conclusion: Professor Yessios: Effective Foreign Langauge Teacher

Just like the passage, the conditions have been negated but not reversed. So this answer choice features the same flaw as the passage and is correct.

Key Takeaway:
Flawed Parallel Reasoning questions, particularly diagrammable Flawed Parallel Reasoning questions, can be a tedious time-suck on an exam. However, thoroughly developed diagramming skills and a strong understanding of the flaws can save valuable time. Experienced test-takers would likely diagram this one out, note the flaw and key features of the diagram, eliminate (A) once they see the "or" is misplaced, and finally select (B) once confirming that it committed the same flaw. If you know what you're looking for on a Flawed Parallel Reasoning question, you can select it and move on without reading all the answer choices.

This one's actually a valid argument, and anything valid is automatically incorrect for a Flawed Parallel Reasoning question.

1. NOT Apprenticeship -> NOT Licensed Plumber
2. Martin: Licensed Plumber
   Conclusion: Martin: Apprenticeship

The variables are negated and reversed, so the conclusion is valid.

This is almost a valid argument, but there's a slight equivocation between "effective mayor of a major industrial seaport" and "effective mayor." Here's how we diagrammed it:

1. Effective Mayor of Major Industrial Seaport -> Thorough Knowledge
2. Mayor Leroux: Effective Mayor
   Conclusion: Mayor Leroux: Thorough Knowledge

We don't know if Mayor Leroux is the mayor of a major industrial seaport. Maybe Leroux is the highly effective mayor of a tiny landlocked town in Oklahoma. The skills required for that job could be very different from the skills required in industrial seaports.

Another valid argument. Recall that "the only" introduces sufficient conditions:

1. Delicious Soup -> Fresh Vegetables
2. This Soup: Delicious Soup
   Conclusion: Fresh Vegetables

This answer choice presents a basic, valid deduction, properly drawn from a conditional statement.