Of the 1,000 chemicals in coffee, less than thirty have been tested,

Question

Of the 1,000 chemicals in coffee,  less than thirty have been tested, most of which produce cancer in laboratory rats.

(A) less than thirty have been tested, most of which produce cancer in laboratory rats

(B) most of which produce cancer in laboratory rats, fewer than thirty have been tested

(C) most of the less than thirty tested produced cancer in laboratory rats

(D) less than thirty of which have been tested, most of them produce cancer in laboratory rats

(E) fewer than thirty have been tested, and most of these produce cancer in laboratory rats

Source:  Master GMAT

shameekv1989 · Answer

Of the 1,000 chemicals in coffee, less than thirty have been tested, most of which produce cancer in laboratory rats.

(A)  less than  thirty have been tested, most of which produce cancer in laboratory rats  - less than can not be used for countable noun

(B) most of which produce cancer in laboratory rats, fewer than thirty have been tested  - Correct - Use of fewer and most of which modifying all the 1000 chemicals

(C) most of the  less than  thirty tested produced cancer in laboratory rats  - less than can not be used for countable noun

(D)  less than  thirty of which have been tested, most of them produce cancer in laboratory rats  - less than can not be used for countable noun

(E) fewer than thirty have been tested, and  most of these  produce cancer in laboratory rats  - "these" is it modifying all the 1000 chemicals or those fewer than 30 chemicals - Incorrect

ravigupta2912 · Answer

Even I arrived at B. Not sure what is the explanation here? E reverses the relationship. Even if it were true, wouldn't it need a past participle? The cancer surely occurs after the testing. The current sentence uses the simple present "produce". I'm kinda confused here.

Posted from my mobile device

Sajjad1994 · Answer

Official Explanation

The original sentence improperly uses  less  instead of  fewer  in reference to a numerical quantity (the number of chemicals tested). Also, the modifier  most of which  is separated from its antecedent ( thirty ), resulting in confusion as to whether  most of which  refers to the thirty chemicals tested or the tests themselves.  Choice (E)  remedies both problems in the original sentence.

The correct answer is (E).

Anshul234 · Answer

egmat  please help
shouldn't the demonstrative pronoun 'these' be followed by the noun it modifies

armaan112 · Answer

"most of which" needs to modify 30 chemicals not 1000

ManavAgrawal · Answer

Why E and not B.

What B says is that 1000 chemicals produce cancer in rats, and only 30 of these have been tested.
Most of 1000 chemicals produced cancer in rats might be right, but how did one come to that conclusion if only 30 have been tested.

The sequence is not right in B.
most of the 30 chemicals produced cancer because only 30 of them were tested. 
Therefore E.

Also, never use less for any countable noun.

minalgambhir · Answer

ERROR ANALYSIS -

1) use of 'which' is wrong - it needs to modify the immediately preceding noun
2) 'less' is used for uncountable nouns, for countable, 'few' is used

ANSWER CHOICE ANALYSIS -

A) use of 'which' is wrong - it needs to modify the immediately preceding noun, 'less' is used for uncountable nouns, for countable, 'few' is used
B) Wrong positioning of the clauses, as per the original sentence, fewer than 30 were tested, most of these produced cancer
C) 'less' is used for uncountable nouns, for countable, 'few' is used
D) 'less' is used for uncountable nouns, for countable, 'few' is used
E) CORRECT

Of the 1,000 chemicals in coffee, less than thirty have been tested,

Prep Toolkit

Top 5 GMAT Debrief Videos

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards

GMAT Sentence Correction (SC - EA only) Questions

Of the 1,000 chemicals in coffee, less than thirty have been tested,

Prep Toolkit

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards