LSAT Explanation PT 29, S1, Q3: There should be a greater use

LSAT Question Stem

Each of the following, if true, strengthens the argument above EXCEPT: 

Logical Reasoning Question Type

This is a Strengthen question. 

Correct Answer

The correct answer to this question is C. 

LSAT Question Complete Explanation

Let's first analyze the argument presented in the passage. The argument claims that there should be a greater use of gasohol, which is a mixture of alcohol and gasoline. The premises supporting this conclusion are that gasohol has a higher octane rating and fewer carbon monoxide emissions than straight gasoline, and that burning gasohol adds no more carbon dioxide to the atmosphere than plants remove by photosynthesis.

To simplify this argument, imagine you're trying to decide between two types of drink: Drink A and Drink B. Drink A is healthier and has fewer negative side effects than Drink B. Therefore, you should drink more of Drink A. This parallels the information in the passage, where gasohol (Drink A) has better properties than gasoline (Drink B), and thus should be used more.

Now, let's create an "Evaluate" question for this argument: "Are there any other factors that might make using gasohol less beneficial than using gasoline?"

The question type for this problem is Strengthen Except, which means we're looking for the answer choice that does NOT strengthen the argument.

a) Cars run less well on gasoline than they do on gasohol.

This strengthens the argument because it provides another reason to use gasohol over gasoline, as cars perform better with gasohol.

b) Since less gasoline is needed with the use of gasohol, an energy shortage is less likely.

This strengthens the argument by highlighting an additional benefit of using gasohol: it helps prevent energy shortages.

c) Cars burn on the average slightly more gasohol per kilometer than they do gasoline.

This answer choice does not strengthen the argument. In fact, it weakens it by suggesting that using gasohol might have a downside: cars need more of it to travel the same distance as they would with gasoline. This could lead to higher costs or other negative consequences.

d) Gasohol is cheaper to produce and hence costs less at the pump than gasoline.

This strengthens the argument by providing another advantage of using gasohol: it's more affordable for consumers.

e) Burning gasoline adds more carbon dioxide to the atmosphere than plants can remove.

This strengthens the argument by showing that gasoline has a more negative impact on the environment than gasohol, further supporting the claim that we should use more gasohol.

The correct answer is C, as it does not strengthen the argument and instead introduces a potential drawback of using gasohol.