Q26 - At night, a flock of

[rdown2b]

Can someone tell me why the answer is A. I thought it would be b...

[timmydoeslsat]

The answer is E for this problem! Double check your answer key. We don't want a faulty answer key!

This is not an argument. It is a set of statements/facts.

This is essentially a must be false type of question. It is asking us which one of the claims (answer choices) can we look at and say, "We have JUSTIFICATION for why this answer choice (claim) is not true."

The set of statements can be summed up like this:

Most of the time, at night, a flock of crows will perch close together in a roost (small wooded land).

Each morning, crows leave this roost and fan out in small groups to hunt and scavenge the area.

For most flocks, the crows' hunting area extends AS FAR as 60-80 miles from the roost.

Most of the time, a flock will continue to occupy the same roost for several consecutive years.

When a flock abandons the site for a new one, most of the time, the new site is less than five miles away.


On questions like this, I always like to pay attention to conditional words and quantifiers like some, most, all, none.

I often see the correct answer on a must be false question hit on this idea.

We really cannot prephrase an answer to this, we need to look at the choices.

A) We have no understanding of the REASON the crows abandon their roost site. Thus, we have no justification to reject this claim.

B) This seems very reasonable and it not subjected to rejection based on our statements.

C) That could be the case. We know that most of the flocks do their hunting within an 80 mile space of the roost, so it is not rejected by the statement.

D) We do not know how difficult it is to force a flock of crows from their roost site. Thus, we have no justification to reject it.

E) Remember our last statement of the stimulus.

When flock abandons site for a new one ---> New one is usually less than five miles away.

Could it be the case that most of the time, a flock of crows move to a new site because the area it has hunted has been depleted of sources?

I don't see how that could be. Most of the time, these new roost sites are less than five miles away. So if the hunting area was depleted, how is moving less than five miles away going to help your situation?

[jionggangtu]

the reason why we don't choose A is that we are not given the reasong of moving from the stimulus.

But couldn't this also be the reason we don't choose E, as E is also talking about the reason.

We don't know if moving five miles away is enough or not, we don't know the volume of food they can find can support them for how long, we don't know how much they eat everyday.

[ManhattanPrepLSAT1]

Good question jionggangtu! So you're right that we aren't given the reason for why the birds move, but we do know that they usually only move about 8 kilometers away. We also know that their hunting range extends up to 100 to 130 kilometers from the roost. If they're only moving 8 kilometers away, that wouldn't impact their hunting area very much, and so it shouldn't be that they moved in response to a depleted hunting territory. The new territory would still be almost entirely depleted, so answer choice (E) can be rejected.

However, it's possible that the birds moved because they're flock had gotten bigger and that they needed a larger roost. Answer choice (A) may or may not be true, and so cannot be rejected.

Hope that helps!

[shirando21]

Great explaination! Thank you so much. number matters!

[brandonhsi]

It seems it is a must be false type question to me.

Looking at (E), I thought it is still possible that (E) could be true, because there is still some NON-overlapping areas after the move. Although the non-overlapping area is really small, but it is there. Then after I saw the word "most" in the question prompt, I would say (E) is the best answer.

My question is what is the most efficient way to solve this question? Trying to eliminate the wrong answers by being "could be true" doesn't seem to work too well.

Thanks!

[christine.defenbaugh]

Great question, brandonhsi!

This is very similar to a "must be false" question, but you're right that it's not actually quite as strict as that.

Consider the relationship between the "must be true" inference question and the "most strongly supported" inference question. A "must be true" inference is one that is more or less provable by the information given. However, an inference that is "most strongly supported" may not be 100% provable, though there still must be a great deal of strong evidence backing it. In other words, it must be pretty darn likely to be true, even if it does not HAVE to be true.

This question prompt bears the same relationship to a "must be false" question as the "most strongly supported" does to a "must be true". As a result, we cannot apply the strict analysis of eliminating things that are even remotely possible. Instead, we must eliminate things that we really have zero evidence one way or the other for.

The correct answer is different - we DO have evidence about (E). We cannot say for certain it is false, but we have information that would strongly support the conclusion that (E) is wrong. Since the flocks generally move such a tiny distance, and thus generally keep the majority of their hunting grounds the same, it would really weird if they were usually moving roosts because the hunting area was out of food!

Just as it is on a "most strongly supported" question, the best question to ask yourself on each answer choice is simply "do I have information from the stimulus that would seem to support or undermine this?" You're not looking for categorical proof - just any direct support (against the answer, in this case).

Does that help clear up the strategy here?

[joewoo198256]

Great question, brandonhsi!

This is very similar to a "must be false" question, but you're right that it's not actually quite as strict as that.

Consider the relationship between the "must be true" inference question and the "most strongly supported" inference question. A "must be true" inference is one that is more or less provable by the information given. However, an inference that is "most strongly supported" may not be 100% provable, though there still must be a great deal of strong evidence backing it. In other words, it must be pretty darn likely to be true, even if it does not HAVE to be true.

This question prompt bears the same relationship to a "must be false" question as the "most strongly supported" does to a "must be true". As a result, we cannot apply the strict analysis of eliminating things that are even remotely possible. Instead, we must eliminate things that we really have zero evidence one way or the other for.

The correct answer is different - we DO have evidence about (E). We cannot say for certain it is false, but we have information that would strongly support the conclusion that (E) is wrong. Since the flocks generally move such a tiny distance, and thus generally keep the majority of their hunting grounds the same, it would really weird if they were usually moving roosts because the hunting area was out of food!

Just as it is on a "most strongly supported" question, the best question to ask yourself on each answer choice is simply "do I have information from the stimulus that would seem to support or undermine this?" You're not looking for categorical proof - just any direct support (against the answer, in this case).

Does that help clear up the strategy here?

Crystal Clear! This is some kind of using your common sense to solve the problem.

[Yu440]

Hello,

I answered this question correctly but I was tempted by D. In the stimulus it says "normally, a flock will continue to occupy the same roost for several consecutive years, and when it abandons a roost site for a new one, the new roost is usually less ..." Doesn't this confirms the fact that the crows changes to a different site every few years? Hence it contradicts with D "it is extremely difficult to force it to abandon that site for another"?

Thanks

[ohthatpatrick]

Are you saying the stimulus contradicts (D) because (D) is saying " you won't be able to get this flock to switch roosts" while the stimulus says "the flock will normally switch roosts every few years"?

If so, I think you're just missing the distinction between the 'normal' idea ... a roost of crows deciding on its own to abandon a roost site for a new one,
vs. the 'forced' idea in (D), in which a roost is FORCED to move to another site.

(D) could be true, meaning it's super hard to force a roost to abandon that site, and it wouldn't preclude the idea that every few years the roost CHOOSES to abandon that site.

Hope this helps.