LSAT 108 | Section 3 | Logical Reasoning: Q5

LR Question 5 Explanation

QUESTION TEXT: Researchers have developed a membrane …

QUESTION TYPE: Flawed Reasoning

CONCLUSION: Oxygen-removing fridges will be way less expensive than current models long-term.

REASONING: The new membrane removes oxygen and kills bacteria, so food doesn’t need to be kept as cold and energy costs will be reduced.

ANALYSIS: The author goes from lower operating costs (electricity) to lower overall costs. But a product can have lower operating costs and still be more expensive overall.

The argument never considers:

• How much the new fridge costs to build
• How expensive the membrane is
• How much it would cost people to buy one

Let’s say current models cost about $1,000 but have $5 operating costs daily. This new model costs $10,000 but uses about $2.50 daily. It’s not cheaper overall.

___________

1. CORRECT. The argument ignores the possibility that building or retrofitting these fridges could be extremely expensive. Even if energy costs are lower, huge upfront costs could mean the fridge isn’t less expensive in the long run.
2. Consumer discomfort might affect popularity, but the conclusion is about cost, not whether people like the fridges.
3. We don’t need to know how the membrane was developed to evaluate whether the fridges will be cheaper.
4. The argument isn’t comparing how well the two refrigerators prevent spoilage. It assumes the new technology works. Even if current fridges are already very effective, that doesn’t address whether the new ones are cheaper.
5. The inconvenience of food spoilage is irrelevant. Again, the conclusion concerns expense, not convenience.