LSAT 130 | Section 1 | Logical Reasoning: Q1

LR Question 1 Explanation

QUESTION TEXT: Commentator: Although the present freshwater supply

QUESTION TYPE: Necessary Assumption

CONCLUSION: We’ll need to restrict human water use in the near future.

REASONING: We have enough freshwater now, but over the next few decades the human population will increase quite a bit.

ANALYSIS: There are two necessary assumptions:

We couldn’t make more freshwater.

People won’t naturally become more efficient with freshwater.

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1. This tells us what humans will do with restrictions. But the argument is about whether restrictions are necessary in the first place.
2. It doesn’t matter if freshwater has diminished a bit: it’s still adequate for today. And the argument doesn’t depend on future diminishment, either.
3. CORRECT. If this is true, then we might still have enough water even without restrictions. (Desalination is one possibility.)
   Negation: The freshwater supply will increase enough to meet the future needs of mankind.
4. This is a tempting trap. An “appreciable effect” is nice, but it may not be enough. I.e. maybe we’ll need 50% more, but this attempt only gets us 10% more. We’d still need restrictions.
   (Also, technically this doesn’t specify a positive effect. Maybe we’ll bungle our attempt and decrease the total supply.)
5. It doesn’t matter about what happened in the past. If we can’t replicate those past increases then they are irrelevant.