#14- Global Reference, Must Be True

[Administrator]

Complete Question Explanation

The correct answer choice is (C).

Answer choice (A):

Answer choice (B):

Answer choice (C):

Answer choice (D):

Answer choice (E):

This explanation is still in progress. Please post any questions below!

[ChicaRosa]

Is C correct because of ln 10-12?

Thanks!

[Adam Tyson]

In short, yes! Those lines tell us that asteroids, in addition to the sun and Earth, contain iron, and that's enough for us to answer the question posed in C with a confident "yes". Winner! Good job, Chica!

[lunsandy]

Hi Powerscore,

I have a question on how to approach questions like this. Do I approach this like a MBT/MSS?

I chose A because I thought that we have enough info from the passage to say no, the iron content of Earth cannot exceed 50% of its total mass as stated by line 40-42. It doesn't say how much iron exactly but we know it's less than 10% because of the 90% is hydrogen and the remaining is helium.

Thanks a lot!

[Adam Tyson]

This is most definitely a Must Be True question, lunsandy, because we are looking for the text in the passage to provide the answer to the question. We need proof! That's the case with most RC questions, by the way - they tend to fall into that category and require evidence lifted directly from the text, following the same "Fact Test" that we apply to these questions in the LR sections.

Careful about that math, though! That was a trap answer, because it's the SUN that is 90% hydrogen, not the Earth! Answer A deals with the iron content of the Earth, and all we know is that it has SOME iron (not how much or what percentage).

Answer C, though, is proven by the text, because the author told us beginning at line 10 that asteroids also contain iron. We therefore know that it is more than just the sun and the Earth.

Beware those traps, and read carefully!