Logical reasoning PrepTest 132 · Section 2 · Question 20

Incorrect. This doesn't explain how the new theory sets their age younger than the old one, and younger than the age of the universe.

Incorrect. If anything, making the universe younger makes the paradox worse!

Correct. Argument or Facts:
Facts

Question Type:
Paradox

Stimulus Summary:
A: Old estimates made stars older than the universe, which is impossible. My new estimates have the stars farther away and thus brighter than old estimates, resolving the paradox.

Answer Anticipation:
Interestingly, this Paradox question has the Astronomer insisting that she's resolved an earlier paradox! However, it's unclear that she actually has, so we need to find the information that connects her explanation for how she resolved the paradox with an actual resolution of it!

To come up with an anticipation, we should take a look at how the new theory which supposedly resolves the paradox compares to the old one. First, the paradox itself has to do with the age of the stars—they are older than the universe itself, an impossibility. So the correct answer is going to have to deal with the age of stars.

Second, to figure out the explanation for this, let's look at the two key differences between the theories: the new theory has the stars farther away from Earth, and the new theory has the stars as brighter than the old theory.

So the correct answer is going to have to use either distance or brightness to establish that the stars are younger than in the old theory (or the universe is older, but these details are about the stars and so that's a more likely avenue for the correct answer). Additionally, since the Astronomer specifically brings up brightness, and there would be no reason to do so if her theory resolved the discrepancy just based on distance, that's more likely to be in the correct answer.

So let's find an answer that says brighter stars are younger!

Answer Explanation:
The new theory suggests that the stars are brighter than the old theory, thus resolving the paradox about their being older than the universe. If brighter equals younger, then the new theory has the stars younger than the old theory, thus potentially bringing their age under that of the universe and resolving the paradox.

Key Takeaway:
Comparisons are usually key to answering Paradox questions. Look for any comparisons and see how they relate to whatever the paradoxical situation is!

Incorrect. This answer broadens a premise to include all celestial objects, not just stars. But only stars are relevant to this paradox, so this answer doesn't do anything to the stimulus.

Incorrect. This answer doesn't address the paradox at all, so it's out of scope.