Self-study
Five thousand of the 50,000 books published in country Z in 1991 were novels. ███████ ██ ██ ███ █████ ████████ ██ ███████ █ ██ ████ ████ █████ ██ █████ ███████ █████ ███ █████ ████ ████████ ██ ███████ █ ██ █████ ██ ████ ████ ███████████ ██ ████ ████ █████ ██ █████ █████████ ██ ███████ █ ██ █████
Summary
The author concludes that at most 25% of the films released in 1992 were based on books published in 1991. His reasoning is that 25% of the films released in 1992 were based on novels published in 1991.
Missing Connection
The author’s conclusion is about books, but his premise is about novels. What if there were movies based on books (e.g. biographies) that aren’t novels? We need to close this gap in the argument. We could do so by adding the assumption that all movies released in 1992 that were based on 1991 books were based on novels.
11.
Which one of the following, ██ ████████ ██████ ███ ██████████ █████ ██ ██ ████████ ██████
a
None of the ███████ ████ ██ █████ ████████ ██ ████ ████ ███████ ██ ████████████ ██████████
This is irrelevant, because the conclusion is about the source material of the films (novels vs. other kinds of books), not the professional background of the screenwriters.
b
None of the █████ ████████ ██ ███████ █ ██ ████ ████ █████ ██ █████ █████ ████ ███████
This is saying that, if a film based on a book was released in 1992, then it was based on a novel. If so, the 25% of 1992 films based on 1991 novels are the only films based on 1991 books. And the conclusion that 25% is the max percentage of such films is guaranteed.
c
None of the █████ ████ ████ █████████ ██ ███████ █ ██ ████ ████ █████ ██ █████ ██ █████ ████████ ██ █████
This doesn’t close the gap in the argument: there could still be 1992 films based on 1991 books that aren’t novels. And thus the percentage of 1992 films based on 1991 books could be higher than 25%.
d
Some of the █████ ████████ ██ ███████ █ ██ ████ ████ █████ ██ █████ █████ ████ ███ ████ ████████ ███ ███ █████ ████ ████ █████ ████████
This doesn’t close the gap in the argument: there could still be 1992 films based on 1991 books that aren’t novels. And thus the percentage of 1992 films based on 1991 books could be higher than 25%.
e
Some of the █████ ████████ ██ ████ ██ ███████ █ ████ █████ ██ ██████ ████ ████ █████████ ██ █████
The conclusion is about 1992 films, so 1991 films are irrelevant.