LSAT 158 | Section 2 | Logical Reasoning: Q17

LR Question 17 Explanation

QUESTION TEXT: To establish a human colony on Mars would …

QUESTION TYPE: Necessary Assumption

CONCLUSION: Colonizing Mars is not economically feasible.

REASONING: It requires huge amounts of materials, and transporting them through space is very expensive.

ANALYSIS: What if the materials could be sourced on Mars itself? The argument is assuming that all (or at least most) of the materials have to be transported through space. That’s where the high cost comes from.

But if Mars had usable materials, then you wouldn’t need to transport nearly as much, and the cost problem might go away. So the argument depends on ruling that out.

___________

1. This is too strong. The argument doesn’t require that colonization depends entirely on costs decreasing.
   Negation: Human habitation on Mars can happen without costs decreasing.
2. Even if costs decrease later, the argument is about feasibility given current conditions.
   Negation: It will become cheaper to transport materials in the near future.
3. This is tempting, but it’s too strong. The materials don’t have to come specifically from Earth. They just can’t be from Mars (because otherwise there would be no transportation).
   Negation: There are other sources than Earth for the materials.
4. Irrelevant. The argument is about cost, not whether colonization is worth it.
   Negation: At least one significant benefit would result from colonizing Mars.
5. CORRECT. If Mars could provide the materials, the need for expensive transport disappears, and the argument falls apart.
   Negation: Mars is a source of the required materials.