#11 - Five thousand of the 50,000 books published in country

[Administrator]

Complete Question Explanation

Justify the Conclusion-#%. The correct answer choice is (B)

The stimulus here is an interesting one, full of numerical information and relationships. Perhaps the first thing that should jump out at you is how the author goes from 1991 to 1992 in talking about films made from books. The second point of interest is the novels-to-films connection. Let's break down each piece and see what the author has done:

• Premise: "Five thousand of the 50,000 books published in country Z in 1991 were novels." — This seems fairly straightforward, indicating that novels made up 10% of the books published in country Z in 1991. We can also infer here that there were a huge amount of other types of books (45,000 to be precise) that were not novels.
  
  
  Premise: "Exactly 25 of the films released in country Z in 1992 were based on those novels." — This premise moves into 1992, and indicates that just 25 films in country Z in 1992 were based on those 5,000 novels published in 1991. So far we have a funnel of sorts within country Z (and these arrows aren't conditional, just showing a pathway): 50,000 books published in 1991 5,000 of them were novels 25 films released in 1992 were based on those novels.
  
  
  Premise: "Since 100 films were released in country Z in 1992," — We now have a total for films released in country Z in 1992, namely that there were 100 total. Thus, we can conclude at this point that one-quarter of the films released in 1992 in country Z were based on novels published in country Z in 1991.
  
  
  Conclusion: "no more than one quarter of them were based on books published in country Z in 1991" — Here comes the conclusion, and we immediately have a problem. The conclusion doesn't mirror the exact conclusion made above about based on novels released in 1991, but instead broadens the category to based on books published in country Z in 1991. That leap from novels to books is an issue, and this is the hole that must be closed in order to Justify the Conclusion here. How can that be done? By ruling out the possibility that there were films released in 1992 that were based on non-novels from 1991. Or, in other words, making it so only novels were used as the basis for films in 1992.

Answer choice (A): This answer choice is immediately suspect because we don't have any knowledge about scripts. Second, the answer is not confined to country Z but instead talks generally about "films," whereas the argument was just about country Z. So, there are two solid reasons to dislike this answer.

Answer choice (B): This is the correct answer choice. This answer eliminates non-novels as a source for films in 1992, meaning that the conclusion in the stimulus is now true. Since this answer close the hole in the argument, we can now properly conclude that "no more than one quarter of them were based on books published in country Z in 1991" (and indeed, it was exactly a quarter, which is consistent with "no more than a quarter").

Answer choice (C): This answer choice scrambles the years of the films and the novels, and is wrong.

Answer choice (D): This answer choice proves a source other than books published in 1991 for some films, and improves the argument, but it does not justify the argument. You need to select a response that deals with all remaining 75 books, not just some of those books.

Answer choice (E): This answer choice discusses films from the wrong year.

[Jay]

Hi Powerscore.

I got one this right, but just wanted to check something.

If I were to diagram answer choice B (None of the films released in country Z in 1992 were based on books other than novels," I think it is

Films released in country Z in 1992 -> not based on books other than novels

but here, "other than" means "Except" which is one of the necessary condition indicator as explained in powerscore bible.

so, is it

Films released in country Z in 1992 -> (based on books -> novels) ?

Then it gets weird. I've encountered this kind of issue in lsat. Many sentences have multiple necessary or sufficient condition indicators that confuse me sometimes. Little word of advice on this conditional logic issue please!

[Jeremy Press]

Hi Jay,

Your initial diagram was fine, and it was all you needed to get you to the correct answer.

Your diagram was: Films released in country Z in 1992 -> not based on books other than novels

Let's put that in "if, then" terms to make it more understandable: If a film was released in country Z in 1992, then it was NOT based a book other than a novel.

Let's simplify that just a bit: "If a film was released in country Z in 1992, then it was NOT based on a non-novel type of book."

This simplification gets you to the same place your "nested conditional" form of diagramming was going: "If a film was released in country Z in 1992, then the only type of book it could've been based on was a novel."

No need for fancy diagrams. Just translate the statement into terms that reflect the meaning of the conditions. It gets you to the same place, and it gets you the answer you're looking for (because the one-quarter language in the conclusion is only proven if we know that we didn't get any more books made into films than the 25 novels that were made into films)!

I hope this helps!

[FernGully]

I originally selected E because I misread the: "some of the films released in 1991..." as "some of the films released in 1992." Although, even if my misread was true, it wouldn't completely fill the whole left by the argument.

In my review, where it said the answer was B. I reviewed A, C, D, and E, and saw that they were all insufficient and that left me with B. Of course, I was still confused for a couple reasons, but I'll get to that in a moment.

First, let me share my review notes:

Premise 1: 1991 - 5K Novels / 50K Books published

Premise 2: 1992 - 25 films / 100 total films were based on 5K 1991 novels

Conclusion: Only one-quarter of 1992 released films (25 / 100) were based on 1991 books. <---- I underlined books (mentally noting that it did not say novels).

It's a justify question based on the "properly drawn" in the question, which means that I need to completely fill the gap left from the premises to the conclusion: the 25 / 100 book films released in 1992 must only be from 1991 novels.

However, here is where my confusion sets in:

First, aren't novels books?

Second, B says: "None of the films released in country Z in 1992 were based on books other than novels."

If all the released 1992 films (100 total) were based on novels, wouldn't that mean that more than 25 films were based on books? <----- Or, does this go back to my first confusion in assuming that novels are books?

Third, wouldn't a good justify answer say something along the lines of: "none of the released films in 1992 were based on books." Or, is that too easy and direct for the LSAT? Maybe mentally I'm trying to find an answer that fits my expectations?

[Adam Tyson]

You were right to notice the difference between "novels" and "books," FernGully. And you are correct that novels are books. But where you went astray was in misunderstanding the conclusion, and also overlooking that while all novels are books, not all books are novels.

The conclusion is about the math here. We know that in 1992, 25 films were released that were based on novels published in 1991. The stimulus already proves that there could not have been any more films released in 1992 based on any of those 5000 1991 novels. But the author went a little too far in their conclusion when they claimed that there could not be any more films based on BOOKS published in 1991. They would be wrong if even 1 of the other 75 films released in 1992 was based on some other kind of book, like a film based on a biography, or based on a collection of short stories, or on a nonfiction history book.

Since the argument contains that flaw, any answer that justifies that conclusion will have to completely eliminate that flaw. We have to ensure that none of those other 75 films were based on a different kind of book published in 1991. If we add that to the argument, then it would be true that 25/100 films released in 1992 - one quarter of them - were the only ones based on books published in 1991. The other films would all have to be something else, like original stories not based on any previously written material, or based on plays, or poems, or even on books published prior to 1991.

A simpler approach to this argument would be to use the "Mechanistic" method, where you identify the disconnected or rogue elements in the premises and conclusion and then look for an answer that connects them to each other. You identified those elements as "novels" and "books," and they are the key elements because they do not mean the same thing and it is wrong to leap from the former to the latter since there can be other kinds of books. At that point, you may only need to look for an answer that links those two ideas, and answer B is the only one to mention them both. That makes it a winner by default!