Logical reasoning PrepTest 127 · Section 2 · Question 24

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Strengthen

Stimulus Summary:
In the Byzantine Empire, lead seals served their purpose when the letters they sealed were opened, and then they'd be recast. 40,000 lead seals remain, so the total number of these seals must have been much higher.

Answer Anticipation:
The argument's conclusion is that the 40k lead seals that are still around today make up but a small fraction of the total lead seals made during the ancient Byzantine Empire. So what happened to the rest? Well, the argument establishes that when these seals served their purpose, they were melted down and recast since they weren't cheap (though they weren't expensive). That purpose? Sealing letters—so when the sealed letter was opened, the seal was done and could be recast.

However, that statement is very conditional in nature—when the letter was opened, the seal had served its purpose and would then be recast. The argument never actually triggers this conditional by telling us that the vast majority of lead seals were affixed to letters that were then opened. If most letters of the time were never opened, then the lead seals that closed them wouldn't have served their purpose and wouldn't have been recast—and those 40k that are still around might represent a substantial portion of the total.

Answer Explanation:
If most of the lead seals were affixed to documents that were opened during that era, then they had served their purpose and would have been recast. This means the surviving ones were on the minority of documents that didn't serve their purpose, and the total number of seals is much larger than the remaining ones. This strengthens the argument and is thus correct.

Key Takeaway:
Don't forget about all the important conditional keywords—including, as we saw here, "when." The LSAT will sometimes try to slip a conditional by you, and then fail to actually trigger the sufficient condition, thus guaranteeing the necessary condition holds.

Incorrect. Lead seal recasting happens when the document is opened, not destroyed, so this answer is out of scope.

Incorrect. Without knowing what proportion of this lead was earmarked for letter seals, this answer is out of scope.

Incorrect. While this answer would provide a potential explanation for the 40k lead seals still in existence, it doesn't speak to additional documents. Maybe documents of less import were relatively rare in the early Byzantine Empire.

Incorrect. This answer doesn't speak to the lead seals being recycled. In fact, this answer suggests that many weren't, since fewer than 40k were ever in circulation but over 40k are still around today.