The Hardest LSAT Problems

[Cpt.Picard]

I'd like to post various problems from the LSAT and share my approach to solving them. If you believe I've missed something please feel free to chime in. In effort to not violate any regulations I'll avoid posting the actual problem as it's worded in the LSAT instead I'll provide premises and conclusions (if there are any) and then discuss each answer choice.

I'll also try to include what type of question stem it's, what month and year of the LSAT exam it was first presented in, and which number of which section it can be found in.

Note: Let's keep this page primarily focused on the higher difficulty questions. If you're going to discuss a problem please make sure to discuss each answer choice explaining why you think it's correct and equally as important why you think the others are not.

Cpt.P.

[Cpt.Picard]

June 1998, Logical Reasoning, section 2, #26


Bi: At night most flock of crows perch close together in a small place often (some) a piece of wooded land. This place is called “roost”

Bi: each morning (every morning) the crows disperse into small groups in order to hunt and scavenge in the area.

Bi: for most flocks of crows their hunting abilities extend within 60 to 80 miles from their roost.

Bi: Normally (some) a flock will continue to occupy the same roost for several consecutive years

Bi: When the flock abandons a roost for a new roost site the new roost is usually less than 6 miles away (well within the area of its hunting abilities)



Q-stem: Which answer choice cannot be true? Four of the AC’s will either be could be true, must be true, or neutral and the one answer choice which cannot be true or will necessarily be false will be the correct AC.



A. The stimulus doesn’t specify what’s necessary in order for crows to abandon their roost; all we know is when a flock of crows does abandon their roost for a new site it’s less than 6 miles away.

B. There can be many areas within the 60 to 80 mile radius that crows normally (sometimes) hunt and it’s very possible that when a certain area is no longer resourceful they’ll move onto another area within 60-80 miles from their perching site.

C. Although for most flocks the hunting extends to as far as 60 to 80 miles from the perching site it’s still very possible that most of their hunting could occur within an area less 5 miles from their site.

D. The stimulus doesn’t discuss anything about how difficult it would be to force a flock of crows into a new site. We do know that normally (some) flock continue to occupy a site for several consecutive years nonetheless forcing it to abandon the site might prove to be very easy. We don’t have enough information to answer this question.

E. The last statement of the stimulus tells us that:

E1. When the flock abandons their roost site for a new one it’s generally within a five-mile radius.

E2. A-choice E says: when a flock of crows abandons its site for a new one most of the time it’s because the area which it had its previous roost in has been depleted of resources.

E3. If they have the ability to fly between 60-80 miles from their roost to hunt why would most flocks of crows only fly less than 5 miles to set up a new roost? You would expect them to fly further.

E4. I believe this is the only answer choice which somewhat contradicts the premises thus it cannot be true.

[Cpt.Picard]

Health Association:

Bi: In certain studies (in some studies not necessarily all) most of the volunteers that were meat eaters permanently excluded meat from their diets (during the study) and now (after the study) these same volunteers only eat vegetables and fruits.
Bi: these volunteers suffered no ill effects from this transition and many now prefer this diet.
Conclusion: all people who eat meat can change their diets to a meatless one without suffering at all.

Principle: If there’s a study showing that most people who went from a meat eating diet to a meatless diet without experiencing any ill effects and maintained that diet after the experiment then one can conclude that undergoing such a transition is safe for all people.

Flaws: are the people in the study representative of the whole? It doesn’t say they are and so we cannot show that they are. Thus there’s a part to whole flaw present here.

Also, we can think of several flaws inherent in arguments which use “studies” to put forth a view. Such as: what do we know about that group of people? Were they pre disposed to a meatless diet which made them more susceptible to it during and after the study? Were they telling the truth about their diets after the study? Etc.

Critic:

P: the participants in this study were all favorably disposed to the substitution from meat to meatless before they started this transition (before the study began). Interesting to notice that the critic isn’t merely pointing out a possible flaw in the argument rather is claiming that this actually occurred—it’s actually the case that these people were favorably disposed to such a transition. Q: does the critic provide any evidence to support this claim? Let’s find out.

P: And even if these people were not favorably disposed to this diet beforehand many (some) of them didn’t make a complete transition to a vegetarian diet. So, the critic avoids having to provide evidence for his previous claim by conceding that even if it was true that they were favorably disposed the HA’s argument would still be false. Nonetheless, it’s still claiming that these people were favorably disposed and that’s why they were able to not suffer any ill effects during and after the study.
Let’s look at the HA’s conclusion again:

C: All people who eat meat can change their diets to a meatless one without suffering at all.

This is based on the premise that: the volunteers suffered no ill effects and they prefer this diet.
Let’s focus on the premise that these people now prefer this diet in relation to the critics argument.

Question: can people prefer a vegetarian diet while at the same time failing to make a complete transition to that diet? Can’t someone say ‘you know I prefer to not eat meat because of the inhumane way in which animals are killed for human consumption but sometimes I just can’t help myself I need to eat a 12oz. steak’? What’s more if this was true how would it affect the HA’s premise that even though they might prefer to eat a vegetarian diet that they actually haven’t completely made the transition? It won’t.

The second part of the critics argument doesn’t do much to the HA’s view and so we’re now left with one gem that the study is flawed because the members were favorably disposed to the vegetarian diet. Even though we don’t have any evidence of this we might not need one.

If this was a strengthen the argument question we’d definitely want to look for something that stated this missing bit—that the evidence does exist for such a claim.

The question stem: the critics view would most seriously call into question which one of the following conclusions based on the HA’s views?

We already know that the critics view about there not being a complete transition is irrelevant and so any answer choice that tries to use this view to refute an argument cannot be the answer choice we’re looking for. However, if there’s an answer choice that says the HA’s conclusion about people’s transition to a vegetarian diet is safe we know we can at the least cast some doubt on that by using the critics views (assuming has evidence for it) and so any answer choice that reiterates that the HA’s conclusion is true must be false (cannot be true).

AC’s:

A) Most meat eating peoples diets improved when they ate only veggies:
a. Most of the time when meat eating people changed their diets to vegetarian  their diets improved.
i. HA’s conclusion wasn’t about people improving their diet; it was about people’s transition without ill effects. The critics view doesn’t discuss anything about requirements for improving a diet either only that the HA’s argument cannot be true. Therefore this AC is not something the critic’s argument can refute.

B) Of those people who did make an attempt to transition: those who were more favorably disposed to being a vegetarian were the same people who were more likely to succeed.
a. If anything this would be a claim that the critic would agree with since he’s saying something similar to this—the people in the study didn’t suffer ill effects because they were favorably disposed to a meatless diet. So we cannot use the critic’s argument to refute this view and thus it’s not the correct answer choice.

C) The amount of people adopting a vegetarian diet has increased in the last few years:
a. This is totally out of the scope for both HA’s argument and the critics. We don’t know anything about a consensus telling us how many people have made such a transition. So we can’t use the critics view to refute this claim.

D) Those people who were involved in this study and didn’t make this transition did not regret trying to make the transition.
a. Again out of scope: the HA’s conclusion was drawn on the basis of people (most of the volunteers) who did make the transition and those who didn’t are peripheral to the conclusion. Critic’s attacking HA’s claim, HA’s claim has nothing to do with the people who didn’t make the transition, and so in this particular case the critic’s view cannot be used to refute this claim.

E) (Correct Answer) Most people who are told by their doctors to never eat meat again would succeed by doing so.
a. Would these people succeed?
i. HA says that people who eat meat can go meatless and not suffer at all: implied in this statement is two things 1) people can do this, and 2) would not suffer at all.
ii. The critic argues against this conclusion and so naturally argues against both its implications.
iii. Assuming the critic has evidence for his claim we can take his argument and apply it to the answer choice that claims people would succeed in making this transition.
iv. HA: Study of people who transitioned + people were able to transition and suffered no ill effects = (conclusion) people can transition without illness.
v. Critic: HA’s study is flawed, thus his conclusion is baseless. Thus HA cannot claim either that people won’t experience illness or that they can make the transition. Answer choice E says that people could make the transition and this is clearly something the critic’s argument can be used to refute.

[Balthy]

Hate to burst your bubble, but this is almost certainly not allowed on the boards.


Edit: whoops, didn't see that you altered them. Then I guess it's up to mods.

[Cpt.Picard]

I'm interpreting anything that comes directly from the book and the remainder of the information I provide is my own interpretation of the problem.