According to surveys by the National Institute on Drug Abuse

[toro86717498]

Hi, experts

Please share your thoughts and correct my view. Appreciated

According to surveys by the National Institute on Drug Abuse, about 20 percent of young adults used cocaine in 1979, doubling those reported in the 1977 survey.
(A) doubling those reported in the 1977 survey
(B) to double the number the 1977 survey reported
(C) twice those the 1977 survey reported
(D) twice as much as those reported in the 1977 survey
(E) twice the number reported in the 1977 survey
OA:E

(A) is wrong because "those" cannot replace "20 percent of young adults". If this view is correct, is it possible to use "that " here? because it is singular.

(D) is wrong because "as much as" has no referent.

Experts, please confirm my view above and correct me if it's wrong.

Many thanks in advance

[crackverbal]

No it would not. -ing modifiers at the end of a clause must modify the subject of the clause.
-ing modifiers at the end of a clause have 2 functions -
1. Subordinate action
example -
Students can improve their performance on the tests, using an error log. (Here, "using error logs" modifies the subject "Students" and also serves as a subordinate action to the main clause).
2. Effect
example -
Amit ate only salads this month, losing 5 kilos. (Here, "losing 5 kilos" is an effect of the main clause. it also applies to the subject Amit).
hence, "doubling ..." would apply to the subject - 20% of young adults. this would be incorrect.

D - as much as cannot be used to refer to plurals ('those')
for example - scientists have concluded that the planet's crust harbors up to three times as much water as previously thought. (Water is singular)
You can buy as many chocolates as you want. (Here, 'chocolates' - plural. You 'as many as' with plural nouns).

Hope this helps.

[GMATGuruNY]

According to surveys by the National Institute on Drug Abuse, about 20 percent of young adults used cocaine in 1979, doubling those reported in the 1977 survey.
(A) doubling those reported in the 1977 survey
(B) to double the number the 1977 survey reported
(C) twice those the 1977 survey reported
(D) twice as much as those reported in the 1977 survey
(E) twice the number reported in the 1977 survey

The agent of a COMMA + VERBing modifier must be the nearest preceding SUBJECT.
In A, COMMA + doubling seems to refer to 20 percent of young adults -- the preceding subject -- implying that 20 percent of young adults were DOUBLING those reported in the 1977 survey.
This meaning is nonsensical.
Eliminate A.

Generally, an infinitive modifier serves to express the INTENT of the preceding subject.
In B, to double implies that the intent of 20 percent of young adults was TO DOUBLE the number the 1977 survey reported.
Not the intended meaning.
Eliminate B.

In C, those seems intended to refer to young adults.
As a result, a STATISTIC (20 percent) is illogically compared to a NON-STATISTIC (young adults).
Also, those reported in the 1977 survey implies that YOUNG ADULTS were REPORTED in the survey.
Not the intended meaning:
The young adults were not reported; a STATISTIC about the young adults was reported (the number who used cocaine).
Eliminate C.

In D, much cannot serve to refer to a countable noun such as young adults.
Eliminate D.

The correct answer is E.

[toro86717498]

According to surveys by the National Institute on Drug Abuse, about 20 percent of young adults used cocaine in 1979, doubling those reported in the 1977 survey.
(A) doubling those reported in the 1977 survey
(B) to double the number the 1977 survey reported
(C) twice those the 1977 survey reported
(D) twice as much as those reported in the 1977 survey
(E) twice the number reported in the 1977 survey

Hi Mitch

The agent of a COMMA + VERBing modifier must be the nearest preceding SUBJECT.
In A, COMMA + doubling seems to refer to 20 percent of young adults -- the preceding subject -- implying that 20 percent of young adults were DOUBLING those reported in the 1977 survey.
This meaning is nonsensical.
Eliminate A.

Since those refers to plural pronoun, it should replace young adults. So the intending meaning is: implying that 20 percent of young adults were DOUBLING young adults reported in the 1977 survey.

Can you please clarify what's wrong here? Thanks so much.

[GMATGuruNY]

According to surveys by the National Institute on Drug Abuse, about 20 percent of young adults used cocaine in 1979, doubling those reported in the 1977 survey.
(A) doubling those reported in the 1977 survey
(B) to double the number the 1977 survey reported
(C) twice those the 1977 survey reported
(D) twice as much as those reported in the 1977 survey
(E) twice the number reported in the 1977 survey

Hi Mitch

The agent of a COMMA + VERBing modifier must be the nearest preceding SUBJECT.
In A, COMMA + doubling seems to refer to 20 percent of young adults -- the preceding subject -- implying that 20 percent of young adults were DOUBLING those reported in the 1977 survey.
This meaning is nonsensical.
Eliminate A.

Since those refers to plural pronoun, it should replace young adults. So the intending meaning is: implying that 20 percent of young adults were DOUBLING young adults reported in the 1977 survey.

Can you please clarify what's wrong here? Thanks so much.

Young adults cannot be doubled.
Only a VALUE can be doubled.

[Mo2men]

According to surveys by the National Institute on Drug Abuse, about 20 percent of young adults used cocaine in 1979, doubling those reported in the 1977 survey.
(A) doubling those reported in the 1977 survey
(B) to double the number the 1977 survey reported
(C) twice those the 1977 survey reported
(D) twice as much as those reported in the 1977 survey
(E) twice the number reported in the 1977 survey

The agent of a COMMA + VERBing modifier must be the nearest preceding SUBJECT.
In A, COMMA + doubling seems to refer to 20 percent of young adults -- the preceding subject -- implying that 20 percent of young adults were DOUBLING those reported in the 1977 survey.
This meaning is nonsensical.
Eliminate A.

Generally, an infinitive modifier serves to express the INTENT of the preceding subject.
In B, to double implies that the intent of 20 percent of young adults was TO DOUBLE the number the 1977 survey reported.
Not the intended meaning.
Eliminate B.

In C, those seems intended to refer to young adults.
As a result, a STATISTIC (20 percent) is illogically compared to a NON-STATISTIC (young adults).
Also, those reported in the 1977 survey implies that YOUNG ADULTS were REPORTED in the survey.
Not the intended meaning:
The young adults were not reported; a STATISTIC about the young adults was reported (the number who used cocaine).
Eliminate C.

In D, much cannot serve to refer to a countable noun such as young adults.
Eliminate D.

The correct answer is E.

Dear GMATGuru,

1- In OA, I assume '20% of young adults' is a number to make the comparison with 'twice the number reported......' correct?

2- If the above is correct '20% of young adults' is statistic or number, can choice A be changed to:

doubling the number reported in the 1977 survey.

[GMATGuruNY]

Dear GMATGuru,

1- In OA, I assume '20% of young adults' is a number to make the comparison with 'twice the number reported......' correct?

Correct!

2- If the above is correct '20% of young adults' is statistic or number, can choice A be changed to:

doubling the number reported in the 1977 survey.

The OA to SC71 in the OG11 includes a similar construction:
The cameras of the Voyager II spacecraft detected six small, previously unseen moons circling Uranus, doubling...the number of satellites now known to orbit the distant planet.

[Mo2men]

According to surveys by the National Institute on Drug Abuse, about 20 percent of young adults used cocaine in 1979, doubling those reported in the 1977 survey.
(A) doubling those reported in the 1977 survey
(B) to double the number the 1977 survey reported
(C) twice those the 1977 survey reported
(D) twice as much as those reported in the 1977 survey
(E) twice the number reported in the 1977 survey

In C, those seems intended to refer to young adults.
As a result, a STATISTIC (20 percent) is illogically compared to a NON-STATISTIC (young adults).
Also, those reported in the 1977 survey implies that YOUNG ADULTS were REPORTED in the survey.
Not the intended meaning:
The young adults were not reported; a STATISTIC about the young adults was reported (the number who used cocaine).
Eliminate C.

Dear GMAtGuru,

In choice C, can the construction 'twice as many young adults as..........' correct? how could be the sentence look like?

Thanks

[GMATGuruNY]

In C, those sDear GMAtGuru,

In choice C, can the construction 'twice as many young adults as..........' correct?

Proposed revision:
as many young adults as the 1997 survey reported
Conveyed meaning:
The 1997 survey reported many young adults.
This meaning seems illogical.
The 1997 survey reported a NUMBER.
It did not report the young adults themselves.

[Shelve]

Hi, experts

Please share your thoughts and correct my view. Appreciated

According to surveys by the National Institute on Drug Abuse, about 20 percent of young adults used cocaine in 1979, doubling those reported in the 1977 survey.
(A) doubling those reported in the 1977 survey
(B) to double the number the 1977 survey reported
(C) twice those the 1977 survey reported
(D) twice as much as those reported in the 1977 survey
(E) twice the number reported in the 1977 survey
OA:E

(A) is wrong because "those" cannot replace "20 percent of young adults". If this view is correct, is it possible to use "that " here? because it is singular.

(D) is wrong because "as much as" has no referent.

Experts, please confirm my view above and correct me if it's wrong.

Many thanks in advance

Interesting post, thanks for sharing!