LSAT 156 | Section 4 | Logical Reasoning: Q20

LR Question 20 Explanation

QUESTION TEXT: Azalea bushes flourish in acidic soil …

QUESTION TYPE: Necessary Assumption

CONCLUSION: Azalea bushes can be made to flourish in clay soil.

REASONING: Azaleas need acidic soil, and clay soil can be mixed to become acidic.

ANALYSIS: Once you mix clay with other soils, is it still clay soil? The conclusion only works if the mixed soil still counts as clay soil.

If mixing changes it into something else (e.g. a different soil type entirely), then the argument fails, because azaleas would be flourishing in mixed soil, not clay soil.

So the assumption is that clay soil remains clay soil even after being mixed.

___________

1. Too strong. The argument only needs that some mixtures can be acidic, not all.
2. CORRECT. This ensures that the mixed soil still counts as clay soil.
   Negation: Clay soil that is mixed with other soils is not still clay soil.
3. Also too strong. It says all mixtures result in acidic soil, which isn’t required.
4. What other plants do have no bearing on azalea bushes. Totally irrelevant.
5. This isn’t required either. The conclusion is only that they can flourish, not how well they do comparatively.