According to surveys by the National Institute on Drug Abuse, about 20

Question

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

girisshhh84 · Accepted Answer

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 -   doubling those  implies doubling people - Sounds awkward. 
(B)  to double the number  the 1977 survey reported-  to double the number  implies -  they did what they did(used cocaine) in order to double the number - sounds awkward. 
(C)  twice those  the 1977 survey reported -   twice people  - Sounds awkward, rather have been twice the number of people. 
(D)  twice as much as those  reported in the 1977 survey-   twice as much as those  implies that they used cocaine twice as much as people (and not the number of people)- Sounds awkward . 
(E)  twice the number reported  in the 1977 survey -   Twice the number reported  Perfect construction implying that the number of people in 1979 who used cocaine was double the number of people in the 1977 survey. .

So the answer is E .

VeritasPrepBrian · Answer

Nice catch, scheol - the presence of "those" in D should tip you off that something is wrong.

"Those" is clearly plural, but "much" is a singular modifier ("many" would be the plural), and the two would have to be part of the same comparison. So D is contradictory just at that.

"Those" really should refer to "the number", which is what was reported, so regardless that's wrong. E correctly compares the 1979 number to the new number, and is therefore correct. Nice work!

hanumayamma · Answer

For ex: The percentage of increase in new CPU’s performance is twice the number to its predecessor’s ones.

(A) doubling those reported in the 1977 survey  Doubling incorrectly modifying the meaning – eliminate it ]

(B) to double the number the 1977 survey reported  This is changing the meaning – eliminate it ]

(C) twice those the 1977 survey reported  Number is compared people – eliminate it ]

(D) twice as much as those reported in the 1977 survey  Number is compared people – eliminate it ]

(E) twice the number reported in the 1977 survey  The number is compared correctly – hold it ]

Answer: E

dushver · Answer

Answer option E.
Anirudh, both "Doubling" & "to double" when used sound as if 'about 20 percent of young adults' were causal to the increase in numbers. What essentially the author wants to mean is that tha 'number of young adults using cocaine' 'now' compared to '1970 survey' is double.

Option E takes care of this error making it more precise.

You might want to look at this sentence from OG11 for more explanation involving such usage..

The gyrfalcons, an arctic bird of prey, has survived a close brush with extinction; its numbers are now five times greater than when the use of DDT was sharply restricted in the early 1970s.

seekmba · Answer

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 - '20% percent'   is compared to 'young people'
(B)  to double  the number the 1977 survey reported - surveys dont report.
(C) twice  those  the 1977 survey reported - '20% percent'   is compared to 'young people'
(D) twice as much as  those  reported in the 1977 survey - '20% percent'   is compared to 'young people'
(E) twice the  number  reported in the 1977 survey - '20% percent'   is correctly compared to 'number'

devpanda · Answer

I am not an expert... But this is how I got to the answer...

51. 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 --  What is those pointing to?? Replace "20 percent of young adults" in the later...and not proper 
(B) to double the number the 1977 survey reported --  not proper 
(C) twice  those  the 1977 survey reported 
(D) twice as much as  those  reported in the 1977 survey --  What is those 
(E) twice the number reported in the 1977 survey -- correct

Still, I am looking forward from the experts on their approach

blueseas · Answer

hi ankur,

option E :==>NUMBERS ARE COMPARED TO NUMBERS AND NOT PERSON TO NUMBERS.

lets see: 20 percent of X=RESULT==>If you see..result is always a numerical value.... whenever there is mathematics ...it is going to give you value. 
for example: if you have 100 gm protein==>if i say 20 percent of protein you will burn while running==>what does this mean=>20 gm protein you will utilise while burning===>thats a numerical value===> so takeaway is that whenever you have PERCENT OF SOMETHING===>then you should always compare to numerical thing..and not to any other thing.

moreover in option C THOSE ==>it ise referring to children so we cant compare  number with children .

hope it helps

soods26 · Answer

A,C and D are eliminated because we are trying to compare the percentage of young adults reported for cocaine use. We are not comparing the number of young adults or young adults between 1977 and 1979; we are rather comparing the percentage, which is a number. Meaning the sentence is reporting percentage as a number, which is 20 for the year 1979. The sentence means to say that the percentage reported in 1977 was 10 percent.

OC: E

kinjiGC · Answer

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.

First of all, there is no cause and effect and the next sentence fragment is just to add comparison between the numbers in 1979 and 1977.

A.  doubling  those reported in the 1977 survey -> Doubling is a verbing modifier and suggest that sentence is an effect of the previous clause which is not the case.

B.  to double  the number the 1977 survey reported -> to double shows intent. The sentence just shows a comparison and doesn't say that anything is done  to double  anything

C. twice  those  the 1977 survey reported -> those refer to adults whereas we are comparing number of adults in 1979 and 1977.

D. twice  as much as those  reported in the 1977 survey -> similar issue as option C)

E. twice the number reported in the 1977 survey -> twice the number is the correct comparison.

Twice is an adjective or an adverb which can modify a noun or an adjective wheras double can act as as a verb or or an adjective.

mvictor · Answer

A. doubling those reported in the 1977 survey 
awkward structure, comma+ing serves as a noun modifier. But since the comma+ing modifier must associate with SV of the clause that it modifies, in our case it does not make any sense.

B. to double the number the 1977 survey reported 
to+verb is used to show purpose. This choice alters the meaning of the sentence. Now it implies that 20% of young adults used cocain so that to double the number… illogical.

C. twice those the 1977 survey reported 
2 independent clauses connected only by a comma

D. twice as much as those reported in the 1977 survey 
“as much as” used with people. Much is used with uncountable nouns only.

E. twice the number reported in the 1977 survey 
Correct answer choice. Now the underlined portion serves as noun (twice the number) + noun modifier (reported)

imnareshk · Answer

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 - DOUBLING has distorted the actual meaning of the sentence.

(B) to double the number the 1977 survey reported - the 20 % have intentionally doubled the number, which is not the actual meaning

(C) twice those the 1977 survey reported - Wrong comparison - Number compared to people.

(D) twice as much as those reported in the 1977 survey - Wrong Comparison - Same as C

(E) twice the number reported in the 1977 survey - Number Compared to Number. - CORRECT.

suganyam · Answer

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.

Those is referring to adults or 20 percent of young adults on the whole?
 zillion thanks in advance

Krishchamp · Answer

Can someone please explain me the usage of 'double' and 'twice' on the GMAT and help me understand the difference between them?

prakhar992 · Answer

Do this question again.

It is clear that in this question we are modifying the "20 percent of the adults". how can you modify percent to the number? Please explain.  daagh  sir,  GMATNinja .

GMATNinja · Answer

The expression "about 20 percent of young adults" refers to a NUMBER of people: there is some total number of young adults, and we are talking about 20 percent of that total number. In other words, 20 percent of equals , and it's okay to refer to twice . Of course, this question was written in the 80s, so I wouldn't lose much sleep over it.

SairamRamo · Answer

(A) doubling those reported in the 1977 survey
  those  refers to young adults, but the comparison here is about number

(B) to double the number the 1977 survey reported
 participle usage is incorrect here

(C) twice those the 1977 survey reported
  those  refers to young adults, but the comparison here is about number

(D) twice as much as those reported in the 1977 survey
  those  refers to young adults, but the comparison here is about number

(E) twice the number reported in the 1977 survey
 no error

nkme2007 · Answer

girisshhh84  But, the option E is talking about number where as it is mentioned 20%. Is the comparison correct?

daagh  Please help.

yashikaaggarwal · Answer

Twice the number is the number of cases reported in 1977 which was half of that of 1979. Not the other way round! 
20% is the number reported in 1979 which is double of that of reported in 1977.

Posted from my mobile device

jabhatta2 · Answer

ReedArnoldMPREP  - how would you pick (e) over (c) ?

too me (c) seems okay.

here is my analysis on (c)

people keep saying (c) has a comparison problem - i am not sure i see it 
- i dont believe " twice or double " are comparison markers to begin with

there is a clear antecedent for "those" 
-- the antecedent of " those " is 20 % of adults (20 % of adults is plural per my understanding)
-- analogy : 10 % of girls in class 1A  are taller than  those in class 1b

people are saying (c) has a pronoun issue 
- i dont see why  those   is wrong ==  those  has a modifier in front 
- the modifier in front of  those  is the "the 1977 survey reported"
- that way the  those  is not a stand-alone pronoun ( those  is attached to a modifer)

According to surveys by the National Institute on Drug Abuse, about 20

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According to surveys by the National Institute on Drug Abuse, about 20

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