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Course: LSAT > Unit 1
Lesson 8: Logical Reasoning – Worked examples- Identify the conclusion | Worked example
- Identify an entailment | Worked example
- Strongly supported inferences | Worked example
- Working with disputes | Worked example
- Identify the technique | Worked example
- Identify the role | Worked example
- Identify the principle | Worked example
- Match the structure | Worked example
- Match principles | Worked example
- Identify a flaw | Worked example
- Match flaws | Worked example
- Necessary assumptions | Worked example
- Sufficient assumptions | Worked example
- Strengthen | Worked example
- Weaken | Worked example
- Helpful to know | Worked example
- Explain | Worked example
- Resolve a conflict | Worked example
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Strengthen | Worked example
Example video demonstrating one way to approach Strengthen questions.
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- When (B) states "natural cause,' I understand the phrase "natural cause" as meaning and referring to the volcanoes (and meteorites too), as a naturally occurring event that could have created the craters. But if the natural causes are not known to form a straight line, that does not support that the volcano created these eight large craters. What does the phrase "natural cause" refer to?(9 votes)
- ANSWERS
(A) A similar but shorter line of craters that are all the same age is known to have been caused by volcanic activity.
(B) No known natural cause would likely account for eight meteorite craters of different ages forming a straight line.
(C) There is no independent evidence of either meteorites or volcanic activity in the region where the craters are located.
(D) There is no independent evidence of a volcanic event strong enough to have created the high pressure shocks that are characteristic of meteorites slamming into the Earth.
(E) No known single meteor shower has created exactly eight impact craters that form a straight line.(5 votes) - I still don't understand why the answer is B, I feel like that B is self-contradictory. it says "no known natural cause" would make meteorite craters, but isn't meteorite a natural cause itself??(1 vote)
- Hi, wouldn't the answer actually be E since E supports the argument that it is likely not a meteor shower and thus a volcanic eruption? And B says that it might be either but doesn't put emphasis on the likelihood of volcanic?(0 votes)
Video transcript
- [Tutor] "Eight large craters
run in a long straight line across a geographical region. Although some of the craters contain rocks that have undergone high-pressure shocks characteristic of meteorites
slamming into Earth, these shocks could also have been caused by extreme volcanic events. Because of the linearity of the craters, it is very unlikely that some of them were caused by volcanoes and others were caused by meteorites. Thus, since the craters
are all different ages, they were probably
caused by volcanic events rather than meteorites. Which one of the following
statements, if true, would most strengthen the argument?" So let's just make sure we
understand the argument here. So you have these eight craters that run in a long
straight line, so one, two, three, four, five, six, seven, eight, so those are eight craters that run in a long straight line, and they're talking about
is it caused by meteorites? Meteor, let me write
that a little bit neater, meteorite versus volcanoes, volcanoes, and they say
because of the linearity it's unlikely that some of
them were caused by volcanoes and others were caused by meteorites. So it's unlikely to be a mix of them because you know it seems
very low probability that hey, that one's a meteorite, that one's a meteorite and a volcano, and that one's a meteorite, and volcanic activity just happened to be on the exact straight
line in between them. So that's what this statement is saying. "Because of the linearity of the craters", "Because of the linearity of the craters, it is very unlikely that some of them were caused by volcanoes and others were caused by meteorites." And then they say, "Thus, since the craters
are all different ages, they were probably caused
by volcanic activity/events rather than meteorites." So why does that, why does that
seem to rule out meteorites? Well if it was one meteor shower, you could imagine a bunch
of meteors all falling and having the same rough direction, and one falls here, and another one's right
behind it falls here, and another one falls there, and so they're all part of the same event, you could imagine that multiple meteorites part of the same event
at around the same time forming a line as they
collide with the Earth, but they're saying they're
all different ages. So if you're talking about craters caught started at different times, the odds of meteor, one meteorite hitting, and then a few hundred or thousand years, or a million years later another meteorite hitting in this exact same line, that seems very unlikely and so that's why the difference in ages is also
pointing to volcanic events. The linearity implies that
we're probably not a mix and then the different of
ages plus the linearity implies that we're probably dealing, or according to the author,
with volcanic events. Now let's see what would further enhance or strengthen the argument. So choice A, "A similar
but shorter line of craters that are all the same age is known to have been caused by volcanic activity." So one, if they're talking
about a shorter line of craters that are the same age, well one this doesn't apply that strongly. This is a longer line of craters that are different ages. In some ways the different ages makes it a little bit more interesting to explain, and so the shorter line of craters that are all the same
age doesn't really backup what's going on here, and so it doesn't seem to
really strengthen the argument. A shorter line of
craters that are same age is less impressive than what
we're talking about here. B, "No known natural
cause would likely account for eight meteorite
craters of different ages forming a straight line." So this is what I had mentioned. If you imagined meteorites, meteorite craters all of the same time, if they're part of the same meteor shower, well then you could
imagine them all you know they're all traveling together, and they break up as they
or one big rock breaks up as it enters into the Earth's atmosphere into multiple small ones but they're all going the same direction, and then maybe where
they collide with Earth they can form a line of craters. But the fact that there's no natural cause which will likely account
for eight meteorites to fall at different times, I implicitly assume that
when I try to develop this conclusion but here
they're saying it explicitly, so I was kinda doing the work for them but that really helps and
in fact I would put this, I would put this you know
maybe right over here. I would say, "And the craters
are all different ages, and no known natural
cause would likely account for eight meteorite
craters of different ages forming a straight line. Therefore, they were probably
caused by volcanic events rather than meteorites." That would actually make it more cohesive and you'd be less dependent
on someone like me to say hey well, you
know what are the odds of different meteorites at different times of causing the straight line. So I like choice B lot. Let's look at the other
choices just to make sure that we don't like them alright? "There is no independent
evidence of either meteorites or volcanic activity in the region where the craters are located." Well that definitely wouldn't
strengthen the argument, that actually would undermine
the argument a little bit. If you say, if the argument they're saying it's probably volcanic event, but then if we said there's no evidence of volcanic activity in the region, well that would undermine not strengthen so let's cross that out. "There is no independent
evidence of a volcanic event strong enough to have created
the high-pressure shocks that are characteristic of meteorites slamming into Earth." So this okay, this would undermine it. They're saying hey some of
these have the characteristics of these high-pressure shocks and if there's no evidence that
volcanic events can do that, well that would undermine the conclusion that these were probably
caused by volcanic events. "No single meteor shower
has created exactly eight impact craters that
form a straight line." So this one is interesting because they're talking
about a single meteor shower, this is more of the things all
happening at the same time, and so maybe if these
craters were the same age this could help strengthen the argument that it was volcanic, but we're not talking
about all the craters getting created at the same time. So we don't need to think about, even rule out the single meteor shower, so once again I don't think that does it, that doesn't really
strengthen the argument. B I feel very good about.