kittle wrote:
GMATNinja can you please help explain this? Thank you.
Lots of good discussion in this thread already, but here's a recap:
Quote:
(A) Because of the Sun, which is 400 times larger than the Moon, but also 400 times farther away from Earth, so both the Sun and the Moon have the same apparent size in the sky.
Notice the parallel list within the "which" clause: "... which is (1) 400 times larger than the moon, but also (2) 400 times farther away from earth."
If we remove that entire "which" clause, we're left with: "Because of the Sun, so both the Sun and the Moon have the same apparent size in the sky." This reveals a couple issues:
- There's no reason to stick a "so" before the "both" here. Why not just say, "Because of the Sun, both the Sun and the Moon have..."?
- More importantly, the meaning is off. The Sun itself is not the reason why the Sun and the Moon have the same apparent size in the sky. The Sun and the Moon have the same apparent size in the sky because of the Sun and Moon's relative sizes and distances from Earth.
The causal relationship is off here, so (A) is out.
Quote:
(B) The Sun, which is 400 times larger than the Moon, is also 400 times farther away from Earth, so the Sun and the Moon have the same apparent size in the sky.
Here we have an entirely different sentence structure: "The Sun, which is [X], is also [Y],
therefore (so) the Sun and the Moon have the same apparent size in the sky." This properly expresses that the Sun and the Moon have the same apparent size because of what the Sun
is (i.e. its properties relative to the Moon).
(B) looks good. (If you're confused about the comparison in (B), check out
this post.)
Quote:
(C) The Sun and the Moon have the same apparent size in the sky because the Sun, which is 400 times larger than the Moon, and also 400 times farther away from Earth.
Again, we have a parallel list within the "which" clause: "...which is (1) 400 times larger than the Moon, and also (2) 400 times farther away from Earth."
Removing that "which" clause, we are left with: "The Sun and the Moon have the same apparent size in the sky because the Sun." Because the Sun... did
what? We're missing a verb after the because. And again, the Sun itself is not the reason the Sun and the Moon have the same apparent size.
(C) is out.
Quote:
(D) Four hundred times larger than the Moon and 400 times farther away from Earth, the Sun has the same apparent size in the sky as the Moon's.
Notice the possessive "Moon's" at the end of the sentence. This suggests that we are talking about the Moon's
size, and that makes it seem like we're comparing the size that
the Sun has to size that the Moon's
size has.
That doesn't make any sense. The Moon has a size, but the Moon's
size doesn't have a size. (For more on that, check out
this post.)
So we can eliminate (D).
Quote:
(E) Four hundred times larger than the Moon and also 400 times farther away from Earth, so the Sun in the sky has the same apparent size as the Moon.
Notice that the stuff before the comma logically modifies the Sun itself, so we expect "the Sun" to come right after the comma. Instead we get a "so" right after the comma, and that doesn't work:
- "Smarter than the average bear, Yogi always managed to get his hands on a picnic basket." - No problem here -- the opening modifier describes the noun right after the comma (Yogi).
- "Yogi was smarter than the average bear, so he always managed to get his hands on a picnic basket." - This one is fine because we're now using a separate independent clause instead of an opening modifier. The conjunction "so" (or "therefore") can be used to link the two independent clauses.
- "Smarter than the average bear, so Yogi always managed to get his hands on a picnic basket." - This one's not good. We have an opening modifier that doesn't modify a noun right after the comma. And we have an unnecessary conjunction that doesn't link two independent clauses. This is the same problem we have in choice (E).
(E) is out, and we're left with (B).