LSAT Explanation PT 28, S1, Q3: For any given ticket in a

LSAT Question Stem

Which one of the following exhibits flawed reasoning most similar to the flawed reasoning in the argument above? 

Logical Reasoning Question Type

This is a Parallel Flaw question. 

Correct Answer

The correct answer to this question is A. 

LSAT Question Complete Explanation

Let's first analyze the argument in the passage. The structure of the argument is as follows:

Premise: For any given ticket in a 1000-ticket lottery, it is reasonable to believe that that ticket will lose.

Conclusion: Hence, it is reasonable to believe that no ticket will win.

The argument exhibits a flawed reasoning known as the "part to whole" fallacy. It assumes that because a trait (reasonable to believe that it will lose) applies to each individual ticket, the same trait applies to all tickets collectively. However, this is not necessarily true.

Now, let's create an "Evaluate" question for this argument: "Is it possible for any of the tickets to win, even if the probability of each individual ticket winning is low?"

The question type for this problem is PF (Parallel Flaw), and we are asked to identify the answer choice that exhibits flawed reasoning most similar to the flawed reasoning in the argument above.

a) This answer choice is correct because it parallels the flawed reasoning in the passage. It is reasonable to believe that any given card drawn from a deck will not be an ace, but it concludes that it is reasonable to believe that no card will be an ace. This is another example of the "part to whole" fallacy.

b) This answer choice does not parallel the flawed reasoning in the passage. The specific horse discussed in the premise is not a subset of the larger group discussed in the conclusion (the conclusion is about the group of all horses other than that premise-horse).

c) This answer choice presents a different flaw. It concludes that a belief is reasonable based on the fact that another belief is unreasonable, which is not the same as the "part to whole" fallacy in the passage.

d) This answer choice is not a flawed argument. The first sentence is a flawed notion of probability, but if we accepted the first sentence as true, then we would believe the logic of the conclusion.

e) This answer choice exhibits the flaw of reversed conditional logic, which is different from the "part to whole" fallacy in the passage. It assumes that if a group of five-year-old children has an average height of one meter, then Pat, a five-year-old, must be exactly one meter tall.

In conclusion, answer choice (A) is the correct answer because it exhibits flawed reasoning most similar to the flawed reasoning in the argument above.