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Course: LSAT (DEPRECATED) > Unit 1

Lesson 10: Reading Comprehension - Worked Examples

Recognition 1 | Science passage | The Sun

Watch a demonstration of one way to answer a Recognition question from a science passage on the LSAT. Created by Dave Travis.

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  • aqualine seed style avatar for user dsc8122
    I don't like this question on a technical aspect. There is an assumption made of evidence not presented in the passage. Answer C states "In the solar system." The passage does mention all known asteroids contain iron, but it does not state that there are any asteroids in the solar system. Obviously, it is known that we have asteroids within our solar system; however, it is stated that we should not utilize outside knowledge for these questions. Without prior knowledge unrelated to this passage that there are asteroids in our solar system, this question cannot objectively be answered correctly.
    (3 votes)
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  • blobby green style avatar for user Salma Ibrahim
    I initially thought the answer for this was A, because in lines 41-42, the passage specifies that Payne found "90% of the sun is hydrogen and most of the remainder is helium"; therefore, we can answer question A with no, the iron content of the sun does not exceed 50%. In this circumstance, how should I approach this to know which one is the correct answer?
    (0 votes)
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Video transcript

- [Instructor] The passage provides enough information to answer which one of the following questions? Okay, so... So four of these things, we're not gonna be able to answer with the information with the passage. And one of them, the answer will be in the passage. So this is really a question of how much we remembered, but if we need to go back to the passage, we can. Okay. A, does the iron content of Earth exceed 50% of its total mass? I don't know if they said how much iron is in Earth. I don't remember them seeing a number. So this kind of makes me think that that probably we don't know the answer to this. We can look for a little bit later. B, who first proved that the sun generates heat from hydrogen by nuclear fusion? Um, I don't think they told us that. We know that Einstein was involved in like the prove event, but we don't, we don't-- it wasn't about the proof of that. C, do any objects in the solar system other than the Earth and the sun contain iron? Ah yes, I believe that that was mentioned so let's-- They mentioned asteroids, I think. But we can go on back and make sure about that. What percentage of the sun's mass is composed of iron? Let's see. They definitely mentioned that there's iron in the sun. So we can look for that in a minute. Can the fusion of atoms other than hydrogen atoms produce energy? There was no talk of other kinds of fusion. So that's definitely out. We can just get rid of this choice, and get rid of this choice. And now what we can do is we can, you know, look for these other ideas. Does the iron content of Earth exceed 50% of its total mass? Let's have a look this passage. Okay, so... Let's see where we are. Hydrogen and helium, okay. Let's start. We're looking for iron. Orthodox view that the sun was mainly iron, was buttressed by the knowledge of Earth, Earth and all known asteroids. All known asteroids contain iron. So there's our answer. They also don't know exactly how much iron is in Earth. That wasn't mentioned. So we can definitely cross out this one. And we didn't know exactly how much there was there. So we have our answer. Asteroids.