LR Question 23 Explanation
QUESTION TEXT: If the prosecutor wanted to charge Frank with…
QUESTION TYPE: Flawed Parallel Reasoning
CONCLUSION: Frank doesn’t embezzle.
REASONING: Wants to prosecute ➞ Charged
Charged ➞ Embezzle
ANALYSIS: This argument gives a single conditional statement, then negates the necessary condition. We could have correctly concluded that the prosecutor doesn’t want to prosecute Frank. But we don’t know if Frank is an embezzler.
You could call it a concept shift. Prosecuting Frank for embezzlement doesn’t mean Frank embezzles, and not prosecuting doesn’t mean he is innocent.
___________
- This is a different error. It’s a mistaken reversal:
Knew ➞ 10
Incorrect reversal: 10 ➞ knew - This is a different error. It’s an incorrect negation
Lottery ➞ stay home
Incorrect negation:lottery➞stay home - CORRECT. This argument correctly negates the necessary condition of a conditional statement. And then it repeats the concept shift error in the stimulus: we could conclude that Makoto does not believe the oven is on, but it’s very possible that the oven is actually on. Belief ➞ fact, just like lack of prosecution ➞ innocence.
Believe oven on ➞ Rush home
Still at work. Therefore oven actually off. - This answer repeats the same concept shift error, moving from belief about getting a promotion, to actually getting a promotion. But, this argument makes an incorrect reversal. The stimulus correctly negated the necessary condition.
Believed promotion ➞ Come in early
Incorrect reversal: Come in early ➞ actually getting a promotion. - This repeats the belief/fact concept shift. However, the stimulus and answer C both negated the necessary condition of the conditional statement. This answer presents a flawed version of the sufficient condition.
Believe going to be fired ➞come in to work
Flawed sufficient condition: Lucy is going to be fired.
Recap: The question begins with “If the prosecutor wanted to charge Frank “. It is a Flawed Parallel Reasoning question. To practice more Flawed Parallel Reasoning questions, have a look at the LSAT Questions by Type page.
More Resources for Flawed Parallel Reasoning Questions
- Conditional Reasoning Article: Learn about conditional statements.
- LR Diagrams Guide: Learn how to draw LR diagrams.
- Flaw drills: Practice identifying flaws.
- Intro Course lesson: This intro course lesson covers Flawed Parallel Reasoning questions.
- Mastery Seminar lesson: This LR Mastery seminar lesson covers flawed parallel reasoning questions.
While actually taking the test, after identifying the argument in the stimulus and seeing that the argument negates the necessary condition (in this case, the argument negates Frank would have already been indicted), will you try to speed things up by looking for that pattern in the answer choices to eliminate some/all of the answer choices, or do you evaluate each answer choice one by one seeing if it’s parallel?
Good question. Yes, on this one I would first look for negating the negative, as the argument is attempting a contrapositive but bungles it. I don’t eliminate the other answers, but I would start with only C in this case, as that is the only one which negates the necessary. And since C matches the rest, I would be satisfied and pick that.
I look at all the answers, but I don’t consider every aspect of them unless my attempt at finding the right answer fails.
Brilliant. Thank you for the reply. While taking these practice tests, I’ve been using your website, Powerscore’s, and Manhattan Prep’s. Their answers are quite mechanical (which can be helpful), but your answers are by far the cleanest and most intuitive. Thanks for all you do!!