GMAT Club Experimental SC 2-1

Among Options, D is better
But I have doubts in 2 issues
will vs would
&
The Modifier "a lack of knowledge about how " replacing "..by 2100"

( In this case "a lack of knowledge about how " is not modifier, but sentence after 2007 and before, a lack of is additional information ( that is why it is mentioend between two commas ( start and end)

In the original sentence, "rise by between 18cm and 59cm" doesn't sound correct. Proper usage should have been "rise by 18cm to 59cm" . Among all choices, D is the best one, although I would have preferred "would" instead of "will".

My Answer is D

Prediction alreadly has sense of conditinality and hence a conditional verb (could/would) is not required.
Fell is about a 3/5.

thanks for your views. So, using "would" instead of "will" is wrong, or they are interchangeable?

Should be D.

No I dont think they are interchangeable. For example, in subjunctive, you prefer would to will. But I agree with one of the explanations above that prediction already gives an element of uncertainty so adding would would be excessive.

4/5

shkusira, what I meant was, is it okay to use "would" instead of "will" in D. From your comment, I see that it would be excessive to use "would" here.

Future in the Past is used to express the idea that in the past you thought something would happen in the future. It does not matter if you are correct or not.

would is appropriate in this case.

I stick with orignal sentence.. (A)

I don't see any issue with Rise by between 18cm and 59 cm


5/5

The OA is A.

I will post the explanation a bit later - it is still getting polished.

in the OE, could you also explain why the other choices are wrong. Also, is phrase "rise by between 18cm and 59cm" correct? It doesn't sound right.

1. we need "rise by"
2. I think we need simple past of auxiliary verb "will" - i.e. "would"
3. now, "made its predictions" is way more wordy than "predicted". In addition, "its" is potentially ambiguous.

So, I think if point 3 is incorporated into A, A will look great.

Overall, I like the question.

Thank you for your feedback. Again the goal here is to give the writer as much feedback for improvement as possible.
Here are the OA and Explanation - would be fantastic if you could post your feel for the difficulty of this question - let's just put on a level between 600 and 800 - that will of course vary by each test-taker but still:

Below 600
600-650
650-700
700-750
750+

OA: A:

A - is the best choice and answer. Since both events were occurring at the same time, past tense is required and “made” and “were” are correct verb. The idiom, “between x and y”, is also correct in A.

B - is wrong as it is not a complete one. A participle/modifying phrase is not enough to make the sentence complete. Since the first clause is dependent clause, the second clause should be an independent clause, which is intact in A but not in B.

C - is also same as B is.

D - changes the meaning by changing the verb would into “will’. Since the prediction was in the past (unreal past condition), “would” is required not “will”.

E - is also similar to D and has an incorrect verb “rise” in place of the correct verb “would” to make the sentence past unreal conditional.

The 3rd point you made epitomizes the problem with just merely taking sentences off of economist or wikipedia. Sentences that appear on GMAT follow a pattern and give preference to grammar, meaning and concision in that order. First of all the sentence in Q is testing an obscure, does not sound good "rise by between", which IMO can be expressed in a better way.

I guess the writer intentionally changed the would to will in D as a trap. All said, I think that this is atypical of GMAT or probably a real 800 level Q, which needs Ron Purewal/Stacey Koprince of MGMAT or Grumpyoldman/Ian Stewart

Grumpy/Ian,

What do you guys think?

After "rise by", I expect a number not a preposition. Does someone else think the same way?

Although "rise by between" reads awkwardly, I don't think there is a better way to show that smth "rise by" a certain range.

D is the trap conveniently placed by the writer - and I have to admit that I fell into it. I agree that "rise by" needs to be followed by a number but then over here even "between x and y" points to a number, so it should sound ok. If D had "would" in it, I think that would be the best suited answer than A.
For me, this is question is one of the closest that comes to the actual GMAT question for the very fact that these traps generally come a lot in the actual GMAT.
Very good question and very good debate.

"rise by between x and y" can be replaced by "rise between x to y"...

I honestly haven't seen a single sentence with the "rise by between" usage..