The number of people flying first class on domestic flights rose sharp

A sounds right to me. "the number of people" is singular so that makes C, D, and E wrong.

A sounds better than B ..

We could also use twice to indicate a multiple x2, isn't it?

My age is double your age.
My age is twice as your age.
I am two times as old as you.

All the above three sentences mean the same, isn't it?.. none of them refer to frequency, but to a multiple.

The point is, twice or two times could be used for two different meanings:

1. frequency, as you stated (because of the word times)
2. multiple x2, as I mentioned above.

However double can only be used to refer to the multiple x2.

The number of people flying first class on domestic flights rose sharply in 1990, doubling the increase of the previous year.

A. doubling the increase of - -ing participle word correctly links the second part sentence of the sentence to the first.
B. doubling that of the increase in - that does not refer to anything
C. double as much as the increase of . - double and "as much as" are both comparison words. "as much as is used for uncountable things"
D. twice as many as the increase in - twice and "as many as" are both comparison words - Redundancy
E. twice as many as the increase of - twice and "as many as" are both comparison words - Redundancy

souvik101990 merge the topics @shttps://gmatclub.com/forum/the-number-of-people-flying-first-class-on-domestic-flights-80878.html

Yes, in option (B), "that" is used as a pronoun. It needs to have an antecedent. But it doesn't.

(B) The number of people flying first class on domestic flights rose sharply in 1990, doubling that of the increase in the previous year.

What does "that" stand for here?

"that" stands for "the increase" but it hasn't been mentioned before.

e.g.
Democrats have rated the U.N. more positively than Republicans, with Democrats' average approval rating (46%) nearly doubling that of Republicans (24%).

"that" stands for "average approval rating". The pronoun needs an antecedent.

In option (B), the pronoun "that" has no antecedent.

I was thinking that the antecedent refers to the 'number of people' . That is why I chose B. please help explain why B is wrong. thanks

Here's the full sentence again, with (B) inserted:


If we replace the pronoun "that" with "number of people", we get nonsense: "The number of people flying first class on domestic flights rose sharply in 1990, doubling the number of people of the increase in the previous year." I can't make any sense of that at all.

I hope this helps!

"the increase in X" means that X itself has increased. therefore, "the increase in the previous year" doesn't make sense, because the implication would be that the previous year itself had increased (what would that possibly mean?).
eliminate (B) & (D).
**********

"That" refers to the number of people.
b. doubling "the number of people" of the increase in the previous year.

Also note that the correct answer replaces "that" with "increase." You're saying the increase doubled, not the number of people flying first class. Important meaning shift.

"the increase of TIME PERIOD", by contrast, means exactly what it should mean in this particular instance.
Another reason to eliminate (B)
***************

if you say "twice as many", then this construction should be paired with a countable noun.
e.g., twice as many dogs --> "dogs" is a countable noun

if you said "twice as much", then this construction should be paired with an uncountable noun.
e.g., twice as much water --> "water" is an uncountable noun

if the noun in question is already an explicitly numerical quantity, then you should use neither "much" nor "many". instead, you should just use "twice" or "double" by itself.
e.g., twice the increase --> "increase" is an explicitly numerical quantity

these rules are followed pretty closely.
so, for instance:
twice as much water --> correct, since "water" is an uncountable noun (but is not an explicitly numerical quantity)
twice the water... --> incorrect, since water is not a numerical quantity

twice as much as the increase... --> incorrect; redundant
twice the increase... --> correct

So you can not use "as much as/as many as" if the noun(increase) is an explicitly numerical quantity.
and also in (D) & (E), you can not use "MANY" with uncountable noun "increase"
eliminate (C), (D) and (E)

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A implies that the number of people has done the action of 'doubling the incerase' whereas 'the rise' actually doubled the increase. Is this usage okay?

Hi sups3906, you are absolutely right. That's the reason such participial phrases (doubling the increase here) act both as adjective as well as adverbial modifier; adverbial because such participial phrases modify the verb of the previous clause (in this case rose).

When do we need to use that in a question such as this? Like in option B?

Check out this post, particularly "Usage #1: "that” as a pronoun". If I remember correctly, the same issue comes up a few times in this video on comparisons. Hopefully that will help!

@e-GMAT GMATNinja, how can A be the right answer? According to me, its meaning is wrong. Let us have a look at the intended meaning of the question and the conveyed meaning of A.

Ideally the sentence wants to convey this. Let me know if you agree with this.
1988 = 100
1989 = 150 (Increase of 50)
1990 = 150 + 2*50 = 250

Now let's see A:
The number of people flying first class on domestic flights rose sharply in 1990, doubling the increase of the previous year.

The above sentence says two things:
i) the number of people rose sharply in 990
ii) the number of people FFC in 1990 = double of increase of the previous year

If the increase of the previous year was 50 (1988 to 1989) then the number of people FFC in 1990 should became twice of this number. So are we saying that it became 100? That's wrong because it actually became 250 and not 100.

Please explain.

Interesting question! If the sentence were conveying that the number of people flying first class was itself equal to the increase, you'd be right -- those two values must be different. But that isn't what the sentence is saying. Instead, it's telling us that the number of people flying first class increased, and, as a result, the value of the increase doubled. In other words, we're dealing with two different values that have a logical relationship to each other.

If we used your numbers, for instance, we could write, "Because the number of people flying first class rose from 150 to 250, the increase this year (100) was double the increase (50) of the previous year." A little cumbersome to include all those values, but perfectly logical in the same way (A) is logical.

The takeaway: When we have FULL CLAUSE + COMMA + -ING, the "-ING" modifier will often offer us a consequence of the previous clause. One element can be a consequence of another, even if those two elements are not themselves identical.

I hope that clears things up!

Is there a difference between "increase in" and "increase of"?
I originally thought that "increase of" was wrong, as it was not parallel with "rose sharply in 1990".

Typically, "increase in" is followed by the actual thing that is being measured. For example,

"Last year, the US saw an increase in demand for toilet paper."

In this sentence, "demand for toilet paper" is the thing being measured (the thing that has increased).

In choice (A), "of the previous year" is basically acting like a possessive ("increase of the previous year" = "last year's increase"). This is no different than something like this:

"Tim was mesmerized by the crackling of the fire."

The "crackling" belongs to the fire just as the "increase" belongs to "last year."

Note that "doubling..." is simply an "-ing" modifier and is NOT part of a parallel list. We don't have a parallelism trigger (i.e. "and"), so we don't actually have to worry about parallelism here.

I hope that helps!

Hi GMATNinja - is "Twice" always an adverb ?

So it would be wrong to say -- I am TWICE your size ? It should be I am DOUBLE your size.

Hi avigutman - was curious, if you could eliminate D and E had the expression been

Twice as many much as

OR you think the GMAT wouldn't do that ?