LSAT Explanation PT 31, S2, Q21: Bank deposits are credited on the

LSAT Question Stem

Which one of the following exhibits both of the logical flaws exhibited by the argument above? 

Logical Reasoning Question Type

This is a Parallel Flaw question. 

Correct Answer

The correct answer to this question is C. 

LSAT Question Complete Explanation

Let's first analyze the argument in the passage and identify its structure. The argument can be broken down into the following parts:

1. Premise: Bank deposits are credited on the date of the transaction only when they are made before 3 P.M.

2. Premise: Alicia knows that the bank deposit was made before 3 P.M.

3. Conclusion: Alicia knows that the bank deposit was credited on the date of the transaction.

The argument exhibits two logical flaws. The first flaw is a Mistaken Reversal. The passage states that if a deposit is made before 3 P.M., it will be credited on the date of the transaction. However, the conclusion assumes that if Alicia knows the deposit was made before 3 P.M., she also knows it was credited on the date of the transaction. This is not necessarily true.

The second flaw is about what Alicia "knows." The passage tells us that Alicia knows the deposit was made before 3 P.M., but it doesn't mention whether Alicia knows about the bank's policy regarding deposits made before 3 P.M. Without knowing the policy, Alicia cannot be certain that the deposit was credited on the date of the transaction.

Now let's consider an "Evaluate" question for this argument: "Does Alicia know about the bank's policy regarding deposits made before 3 P.M.?" The answer to this question would determine whether the argument is valid or not.

The question type for this problem is Parallel Flaw, and we're asked to find the answer choice that exhibits both of the logical flaws present in the passage.

Let's examine each answer choice:

a) This answer choice exhibits a Mistaken Reversal flaw but doesn't have the "knowing" flaw. Marjorie being a journalist is not enough to conclude that she will be permitted to ask questions.

b) This choice also exhibits a Mistaken Reversal flaw, but not the "knowing" flaw. Just because today is Thursday and Patrice only works on Thursdays doesn't mean Patrice is working today.

c) This choice exhibits both flaws. It has a Mistaken Reversal flaw, as it assumes that if George knows Helen will resign, he knows he will be promoted. It also has the "knowing" flaw, as there's no indication that George knows about the condition of Helen's resignation for his promotion.

d) This choice doesn't exhibit either flaw. It has a Repeat conditional form, which is not present in the passage.

e) This choice doesn't exhibit either flaw. It makes an assumption about Pat's desires based on her career choice, but it doesn't involve a Mistaken Reversal or the "knowing" flaw.

Based on our analysis, the correct answer is (C), as it exhibits both logical flaws present in the passage.