LSAT Explanation PT 24, S2, Q5: Altogether, the students in Ms. Tarnowski's

LSAT Question Stem

Which one of the following arguments contains flawed reasoning that is most parallel to that in the argument above? 

Logical Reasoning Question Type

This is a Parallel Flaw question. 

Correct Answer

The correct answer to this question is D. 

LSAT Question Complete Explanation

Let's first examine the argument in the passage. The passage states that Ms. Tarnowski's class collected more aluminum cans than any other class in the school. The conclusion drawn is that the student who collected the most cans must be in Ms. Tarnowski's class. This argument has a premise and a conclusion. The premise is that Ms. Tarnowski's class collected the most cans, and the conclusion is that the top collector must be in her class. However, this reasoning is flawed because it's possible that the class as a whole collected the most cans, but the individual student who collected the most cans could be in another class.

To help understand this, let's use a simple example. Imagine three classes - A, B, and C - each with three students. Class A collects a total of 50 cans, class B collects 60 cans, and class C collects 40 cans. While class B collects the most cans overall, it's possible that one student in class A collected 30 cans, while the highest collector in class B only collected 25 cans. In this case, the top individual collector is not in the class that collected the most cans overall.

Now, let's move on to the question. This is a Parallel Flaw (PF) question, which asks us to identify the answer choice that contains flawed reasoning most parallel to that in the passage. Let's examine each answer choice:

a) This answer choice states that Mr. Kelly's class planted more trees than Mr. Liang's and Ms. Jackson's classes combined. The conclusion is that Mr. Kelly's students planted more trees than Ms. Jackson's students. This reasoning is not flawed, as it is a logical conclusion based on the premise, so it is not parallel to the passage.

b) This answer choice states that more than half of the students participate in the band and choir. The conclusion is that every student either plays in the band or sings in the choir. This reasoning is flawed because it's possible that some students participate in both activities, but the flaw is not parallel to the passage.

c) This answer choice compares the money raised by Mr. Rowe's class selling candy bars to Ms. Hunt's class holding a raffle. The conclusion is that Mr. Rowe's class sold more candy bars than Ms. Hunt's class sold raffle tickets. This reasoning is flawed because it compares two different fundraising methods, but the flaw is not parallel to the passage.

d) This answer choice states that Ms. Ramirez's class sold the most tickets to the school fair. The conclusion is that the student who sold the most tickets must be in Ms. Ramirez's class. This reasoning is flawed in the same way as the passage, as it's possible that the class as a whole sold the most tickets, but the individual student who sold the most tickets could be in another class. This answer choice is the correct one, as it contains flawed reasoning most parallel to the passage.

e) This answer choice states that Ms. Ventura's class assembled more birdhouses than any other class and had fewer students. The conclusion is that her students assembled more birdhouses, on average, than students in other classes. This reasoning is not flawed, as it is a logical conclusion based on the premises, so it is not parallel to the passage.

In conclusion, the correct answer is choice D, as it contains flawed reasoning most parallel to the passage.