Because the Earth’s crust

[vikram4689]

"an area 100 times greater than a quake". it's pretty obvious that we're comparing an area to a quake, and that of course is not valid. what seems to be the problem?

sir,
the sentence is quake A will devastate an area 100 times greater than quake B. do you think there is any sort of ambuguity in this sentence. ambiguity exists when we get 2 meanings from same sentence. i described the reasons in my last post.

[tim]

sure the meaning is clear, but that's not the point. the point is the grammar mistake in this comparison..

[vikram4689]

sure the meaning is clear, but that's not the point. the point is the grammar mistake in this comparison..

sir,
i am not able to get this. to decide whether helping verb is required or not, i use following rules by ron and as per these we can avoid helping verb. can you please give some examples.

[jnelson0612]

sure the meaning is clear, but that's not the point. the point is the grammar mistake in this comparison..

sir,
i am not able to get this. to decide whether helping verb is required or not, i use following rules by ron and as per these we can avoid helping verb. can you please give some examples.

I'm not Ron but let me give this a shot:

Regarding #1:
I will eat and run.
(here I have a simple parallelism signal "and" so only one helping verb is needed)

Either I will eat or I will run.
(here I have the double parallelism signal so I should repeat the helping verb)

Regarding #2:
Please see Ron's post in this thread regarding helping verbs and ambiguity: sc-parallism-in-comparisons-t3504.html

However, as Tim said, the big problem here is that the sentence is comparing "an area" to "a quake". The GMAT is very strict about comparisons; I can only compare elements that are logically comparable. I have to compare "an area" to another area and "a quake" to something logically comparable. It does not make sense to compare these two elements. This is the problem that we really want you to understand. :-)

[vikram4689]

thanks jamie. i agree 100% with the post you mentioned. in that post, ron says

"in sentence (1), there is no ambiguity (try to conjure an alternate interpretation; you won't be able to), so you don't need the auxiliary verb."

This statement means that we need helping verbs ONLY when two interpretations are MEANINGFUL, no matter how unlikely (like he says "that must be a really short tree" for sentence 2). Although interpretation of 2) in that post is unlikely because of exceptional tree size, interpretation is possible.

Now lets consider the 2 possible scenarios of sentence in this post:
a) quake A will devastate an area 100 times greater than quake B will devastate - entities compared are underlined and comparison is logical so we all agree
b) quake A will devastate an area 100 times greater than quake A will devastate quake B - can quake A devastate quake B ? can an area be greater than a quake. ? Since both of these questions are nonsense, i think we don't need helping verb and this reasoning is similar to one applied by ron in that post when he says we don't need helping verb in 1)

please tell where i am wrong

[asad.alikhan]

for instance, tray A contains more food than tray B is acceptable, but the food on tray A is more than the food on tray B is not acceptable.

Ron, Can you please elaborate on this as I understood this question but am confused on your example

[RonPurewal]

i think we don't need helping verb and this reasoning is similar to one applied by ron in that post when he says we don't need helping verb in 1)[/i]

please tell where i am wrong

well, that discussion treated only
1/ comparisons that are unambiguous and actually make sense, and
2/ comparisons that are ambiguous.

if a comparison is worded unambiguously but doesn't make sense, then it's simply wrong, as in the case of any other sentence with a nonsense meaning.
comparing an earthquake to an area doesn't make sense, so there's no point in even considering the issue of ambiguity for that example -- it's already straight-up wrong.

[ghong14]

Because the Earth’s crust is more solid there and thus better able to transmit shock waves, an earthquake of a given magnitude typically devastates an area 100 times greater in the eastern United States than it does in the West.

(A) of a given magnitude typically devastates an area 100 times greater in the eastern United States than it does in the West


There are several issues with the original sentence.
(1) "it" can refer to several different singular nouns: crust, earthquake, or area. Make sure the pronouns refer clearly to the correct noun.
(2) the comparison construction is "greater X than Y." Here X = "in the eastern US" and Y = "it does in the West." One is a prepositional phrase, and the other is a clause; they are not parallel.

Hope that helps.

_________________
Ben Ku
Instructor
ManhattanGMAT

I don't see the parallel issue here at all. It seems to refer to " an earthquake of a given magnitude". With A the sentence would read:

Because the earth's crust is more sold there and thus better able to transmit shock waves, an earthquake of a given magnitude typically devastates an area 100 time greater in the eastern US than "an earthquake of a given magnitude " does in the west.

Is the issue that the given magnitude should be a comparable magnitude? If so then " the comparison construction is "greater X than Y." Here X = "in the eastern US" and Y = "it does in the West." One is a prepositional phrase, and the other is a clause; they are not parallel. " is NOT valid since there not per se a grammatical parallelism error. Rather it is meaning issue.

[jlucero]

Whether you call this a parallelism issue that makes the sentence's meaning wrong or just say that the meaning of the sentence is wrong is irrelevant. Either way, A is wrong. Ben's point here is that anytime you see the construction "greater X than Y" the X and Y need to be parallel and they are not here. That leads to the major error in meaning you bring up. You can either fix this by using "greater than" or by making X & Y parallel:

A 6.0 earthquake's damage is 100 times greater than a 4.0 earthquake's damage.

The amount of damage is 100 times greater in a 6.0 earthquake than in a 4.0 earthquake.

[rajbharat.87]

for instance, tray A contains more food than tray B is acceptable, but the food on tray A is more than the food on tray B is not acceptable.

Ron, Can you please elaborate on this as I understood this question but am confused on your example

Ron, I understood Ben's Explanation. As a take away,Does "It" in option A refer to Earthquake or not?

[jlucero]

for instance, tray A contains more food than tray B is acceptable, but the food on tray A is more than the food on tray B is not acceptable.

Ron, Can you please elaborate on this as I understood this question but am confused on your example

Ron, I understood Ben's Explanation. As a take away,Does "It" in option A refer to Earthquake or not?

You and I probably understand that it does, but that doesn't mean it's not a little ambiguous. The second point on Vikram's above post about helper verbs probably could be used for a take away here:

to resolve ambiguity
(to take a sentence with 2 possible meanings and reduce to 1 meaning)

That's what restating the actual noun does in the correct answer choice.