Sufficient AssumptionDiff: Medium
Logic Breakdown
Passage Summary: Because all moons have to orbit a planet, the astronaut concludes that all the moons in solar system S4 must orbit planet Alpha.
Conclusion: Every moon in the S4 solar system orbits the specific planet named Alpha.
Reasoning: By definition, every moon must orbit some planet within a solar system.
Analysis: The premise establishes a general rule: Moons orbit *a* planet. The conclusion, however, gets very specific: All moons in S4 orbit *Alpha*. This logic only holds up if there are no other planets in S4 for those moons to orbit. If planet Beta existed in S4, a moon could orbit Beta and still satisfy the definition. To make the conclusion follow logically, we must assume that Alpha is the only planet in solar system S4.
Conclusion: Every moon in the S4 solar system orbits the specific planet named Alpha.
Reasoning: By definition, every moon must orbit some planet within a solar system.
Analysis: The premise establishes a general rule: Moons orbit *a* planet. The conclusion, however, gets very specific: All moons in S4 orbit *Alpha*. This logic only holds up if there are no other planets in S4 for those moons to orbit. If planet Beta existed in S4, a moon could orbit Beta and still satisfy the definition. To make the conclusion follow logically, we must assume that Alpha is the only planet in solar system S4.
Passage Stimulus
Passage Redacted
Unlock Full Passage5.The astronaut's conclusion follows logically if which one of the following is assumed?
Correct Answer
C
If Alpha is the only planet in S4, then every moon in S4 (which must orbit a planet in its solar system) must orbit Alpha. That makes the conclusion logically follow.
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