LSAT 152 | Section 2 | Logical Reasoning: Q3

LR Question 3 Explanation

QUESTION TEXT: Requiring that passwords conform to rules of length…

QUESTION TYPE: Sufficient Assumption

CONCLUSION: Password rules make it more likely that someone will get into a user’s account. (Rule examples: length, complexity, unpredictability)

REASONING: It’s very hard to access an account by guessing: accounts lock after a few wrong attempts. But if password rules make passwords tough to remember, then users will frequently write down the passwords.

ANALYSIS: You could classify this question as “strengthen”, but conceptually it has more in common with sufficient assumption questions: you have to use an answer to link a premise and the conclusion. The only difference is it is probabilistic rather than certain. (Most sufficient assumption questions use 100% certain conditional reasoning). The standard method for sufficient assumption questions is: 1. Identify the conclusion 2. Split it apart 3. Fill in the evidence 4. Spot the gap

So, first you have to find the conclusion: it’s the first sentence. Sentence two starts with “since”, which is a dead giveaway that the preceding sentence is the conclusion. Take that conclusion, and split it apart:

Complex passwords making access more likely

Next you have to fill in the evidence. Sentence 3 is evidence, because it starts with “however”: users write down complex passwords. Fill that in. You can now see a gap between the terms.

Complex passwords ➞ make users write them down making access more likely

So, the answer needs to link “writing passwords down” and “making unauthorized access more likely”. Only one answer includes both concepts. In fact only one answer mentions writing down passwords at all! The above method for sufficient assumption questions is really, really powerful.

___________

1. This is irrelevant. The stimulus says the risk comes from people who can’t remember their passwords. And from common sense we can assume that only a small percentage of people can use such mnemonic devices: the stimulus didn’t say otherwise.
2. This weakens the argument! It suggests you might be able to guess a password after all, because accounts eventually unlock. So password rules can help prevent guessing.
3. CORRECT. See the analysis above. This provides the missing link between the evidence and the conclusion. Complex passwords increase the odds users will write them down, and this answer shows that writing down a password can let someone use it to enter your account.
4. This is not directly relevant. The stimulus only mentioned account locking to show that guessing won’t work. Once the account is locked, it doesn’t matter if it is easy or hard for the owner to unlock. The point is that the lock blocked guessing.
5. This sounds tempting, but the author already said it is “impossible” to guess a password. So, this actually isn’t really saying anything.
   This answer helps clarify what you’re looking for on a question. You’re not merely attacking password rules. Instead you must strengthen the reasoning of the author. And that reasoning was that password rules make people write passwords down.

Recap: The question begins with “Requiring that passwords conform to rules of length”. It is a Sufficient Assumption question. Learn how to master LSAT Sufficient questions on the LSAT Logical Reasoning question types page.