Logical reasoning PrepTest 124 · Section 1 · Question 21

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Flawed Parallel Reasoning

Stimulus Summary:
April showers over 5cm → May . . . tree blossoms
April showers over 5cm → Reservoirs full on May 1
not Reservoirs full on May 1
Therefore - not May . . . tree blossoms

Answer Anticipation:
Conditional logic in a Flawed Parallel Reasoning question? The argument almost certainly features a conditional logic flaw, and mapping the structure of the argument will likely be enough for us to find the correct answer:
A → B
A → C
not C
Therefore - not B

Looking at this, we should be able to tell that the argument is relying on an illegal reversal (or negation) of one of the premises. We can dig in to figure out which one, but since it's captured in our diagram, it's not worth the time—anything that matches this structure will feature the same reversal/negation.

One more note before we head to the answers—this argument features an absolute premise (not Reservoices full on May 1/not C), and an absolute conclusion (not May . . . tree blossoms/not B). That last statement/conclusion isn't a conditional. The LSAT will frequently present the conclusion as conditional when the argument, in reality, presents a premise meant to trigger a conditional chain before reaching the necessary condition of the chain as a conclusion, so we should be careful to avoid any trap answers that do that.

Answer Explanation:
Garlic in pantry → Garlic fresh
Garlic in pantry → Potatoes on basement stairs
not Potatoes on basement stairs
Therefore - not Garlic fresh
Same structure, same flaw—this is the correct answer.

Key Takeaway:
Notice that each of the wrong answers was wrong for the same reason—they didn't have two premises that shared a sufficient condition, as the stimulus did. We were able to eliminate each wrong answer without diagramming them. When dealing with a Flawed/Parallel Reasoning question that features conditional logic, if you're strong at conditional logic, you can identify shared terms and make eliminations based on a mismatch without diagramming. That's going to be much faster than doing a full diagram for each question, so work on conditional logic!

Incorrect. Reading through the first two statements before diagramming, we can see that they don't share a sufficient condition (Burner 2+ minutes; Optimal temperature), so we can eliminate this answer without a full diagram.

Incorrect. Reading through the first two statements before diagramming, we can see that they don't share a sufficient condition (Over 200yo; Set with wooden type), so we can eliminate this answer without a full diagram.

Incorrect. Reading through the first two statements before diagramming, we can see that they don't share a sufficient condition (Mower operates; Foot pedal depressed), so we can eliminate this answer without a full diagram.

Incorrect. Reading through the first two statements before diagramming, we can see that they don't share a sufficient condition(Kiln too hot; Plates crack), so we can eliminate this answer without a full diagram.