GMAT Question of the Day - Daily to your Mailbox; hard ones only

 It is currently 20 Jul 2018, 00:07

### GMAT Club Daily Prep

#### Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

# QOTD: Exposure to certain chemicals commonly used in elementary school

Author Message
TAGS:

### Hide Tags

MBA Section Director
Joined: 19 Mar 2012
Posts: 5126
Location: India
GMAT 1: 760 Q50 V42
GPA: 3.8
WE: Marketing (Non-Profit and Government)
QOTD: Exposure to certain chemicals commonly used in elementary school  [#permalink]

### Show Tags

21 Nov 2017, 14:43
11
00:00

Difficulty:

35% (medium)

Question Stats:

68% (01:18) correct 32% (01:45) wrong based on 508 sessions

### HideShow timer Statistics

Verbal Question of The Day: Day 161: Critical Reasoning

Subscribe to GMAT Question of the Day: E-mail | RSS

Exposure to certain chemicals commonly used in elementary schools as cleaners or pesticides causes allergic reactions in some children. Elementary school nurses in Renston report that the proportion of schoolchildren sent to them for treatment of allergic reactions to those chemicals has increased significantly over the past ten years. Therefore, either Renston's schoolchildren have been exposed to greater quantities of the chemicals, or they are more sensitive to them than schoolchildren were ten years ago.

Which of the following is an assumption on which the argument depends?

(A) The number of school nurses employed by Renston's elementary schools has not decreased over the past ten years.
(B) Children who are allergic to the chemicals are no more likely than other children to have allergies to other substances.
(C) Children who have allergic reactions to the chemicals are not more likely to be sent to a school nurse now than they were ten years ago.
(D) The chemicals are not commonly used as cleaners or pesticides in houses and apartment buildings in Renston.
(E) Children attending elementary school do not make up a larger proportion of Renston's population now than they did ten years ago.

Every question of the day will be followed by an expert reply by GMATNinja in 12-15 hours. Stay tuned! Post your answers and explanations to earn kudos.

_________________
GMAT Club Verbal Expert
Status: GMAT and GRE tutor
Joined: 13 Aug 2009
Posts: 1830
Location: United States
GMAT 1: 780 Q51 V46
GMAT 2: 800 Q51 V51
GRE 1: Q170 V170
QOTD: Exposure to certain chemicals commonly used in elementary school  [#permalink]

### Show Tags

21 Nov 2017, 21:13
4
1
The author concludes that one of two things has happened over the past ten years: either 1) Renston’s schoolchildren have been exposed to greater quantities of the chemicals, or 2) they are more sensitive to the chemicals than schoolchildren were ten years ago. How does the author arrive at this conclusion?

• We are given that exposure to cleaners and pesticides commonly used in schools can cause allergic reactions in some children.
• Over the past ten years, the proportion of schoolchildren sent to school nurses for allergic reactions to THOSE chemicals has increased significantly.

The author states two possible explanations for this increase, but are those the only options? The author's explanation will only hold up if one of the following is assumed:

Quote:
(A) The number of school nurses employed by Renston's elementary schools has not decreased over the past ten years.

A change to the number of nurses doesn't impact the number of students sent to see the nurses, so (A) can be eliminated.

Quote:
(B) Children who are allergic to the chemicals are no more likely than other children to have allergies to other substances.

We are not concerned with allergies to other substances. Regardless of whether children allergic to the chemicals are more likely to have allergies to other substances, we still need to explain why more students are now sent to the nurses because of reactions to THOSE chemicals. The two theories in the conclusion are only meant to explain the increase in the number of schoolchildren sent to the nurses because of THOSE chemicals, so choice (B) is irrelevant.

Quote:
(C) Children who have allergic reactions to the chemicals are not more likely to be sent to a school nurse now than they were ten years ago.

According to the argument, the increase in the proportion of schoolchildren sent to the elementary school nurses is due to either greater exposure to the chemicals or a greater sensitivity to the chemicals. But what if children who have allergic reactions to the chemicals are more likely to be sent to a school nurse now than they were ten years ago? Maybe the amount and severity of the allergic reactions was the same ten years ago but students were simply less likely to be sent to the nurse back then. Maybe ten years ago the teachers simply let the suffering students remain in class with watery eyes and running noses (for example).

That could explain the increase in the proportion of schoolchildren sent to the elementary school nurses, even if students' exposure and sensitivity to the chemicals has not changed. In order for the argument to hold, the author must assume that children who have allergic reactions to the chemicals are NOT more likely to be sent to a school nurse now than they were ten years ago. Choice (C) looks good.

Quote:
(D) The chemicals are not commonly used as cleaners or pesticides in houses and apartment buildings in Renston.

Perhaps the cleaners ARE commonly used in houses and apartments, but we don't care about WHERE the students were exposed to the chemicals. If exposure has increased, whether at school or at home, then the author's argument would be valid. The author does not say that exposure has increased AT THE SCHOOLS, so choice (D) can be eliminated.

Quote:
(E) Children attending elementary school do not make up a larger proportion of Renston's population now than they did ten years ago.

We are trying to explain an increase in the PROPORTION of students sent to the nurses, not an increase in the TOTAL NUMBER of students sent to the nurses. Thus, an increase in the number of students or the proportion of the population attending elementary schools does not matter. We need to explain the increase in the PROPORTION sent to the nurses for those allergic reactions. Choice (E) is not a required assumption and can be eliminated.

Choice (C) is the best answer.
_________________

GMAT Club Verbal Expert | GMAT/GRE tutor @ www.gmatninja.com (Now hiring!) | GMAT blog | Food blog | Notoriously bad at PMs

Beginners' guides to GMAT verbal
Reading Comprehension | Critical Reasoning | Sentence Correction

Series 1: Fundamentals of SC & CR | Series 2: Developing a Winning GMAT Mindset

SC & CR Questions of the Day (QOTDs), featuring expert explanations
All QOTDs | Subscribe via email | RSS

Hit the request verbal experts' reply button -- and please be specific about your question. Feel free to tag @GMATNinja and @GMATNinjaTwo in your post. Priority is always given to official GMAT questions.

Sentence Correction articles & resources
How to go from great (760) to incredible (780) on GMAT SC | That "-ing" Word Probably Isn't a Verb | That "-ed" Word Might Not Be a Verb, Either | No-BS Guide to GMAT Idioms | "Being" is not the enemy | WTF is "that" doing in my sentence?

Reading Comprehension, Critical Reasoning, and other articles & resources
All GMAT Ninja articles on GMAT Club | Using LSAT for GMAT CR & RC |7 reasons why your actual GMAT scores don't match your practice test scores | How to get 4 additional "fake" GMAT Prep tests for $29.99 | Time management on verbal ##### General Discussion Intern Joined: 18 Jan 2017 Posts: 40 Re: QOTD: Exposure to certain chemicals commonly used in elementary school [#permalink] ### Show Tags 21 Nov 2017, 15:32 1 Quote: Exposure to certain chemicals commonly used in elementary schools as cleaners or pesticides causes allergic reactions in some children. Elementary school nurses in Renston report that the proportion of schoolchildren sent to them for treatment of allergic reactions to those chemicals has increased significantly over the past ten years. Therefore, either Renston's schoolchildren have been exposed to greater quantities of the chemicals, or they are more sensitive to them than schoolchildren were ten years ago. Which of the following is an assumption on which the argument depends? (A) The number of school nurses employed by Renston's elementary schools has not decreased over the past ten years. (B) Children who are allergic to the chemicals are no more likely than other children to have allergies to other substances. (C) Children who have allergic reactions to the chemicals are not more likely to be sent to a school nurse now than they were ten years ago. (D) The chemicals are not commonly used as cleaners or pesticides in houses and apartment buildings in Renston. (E) Children attending elementary school do not make up a larger proportion of Renston's population now than they did ten years ago. I think the answer is C. The author of the statement has concluded that the children have either been exposed to a higher level of chemicals or are more sensitive than children were ten years ago but is assuming that there is not an alternative reason why children are going to the nurse. C is the only answer that supports that conclusion since if children were more likely to be sent to the nurse than before, it could be something other high exposure or sensitivity. Senior Manager Joined: 06 Jul 2016 Posts: 417 Location: Singapore Concentration: Strategy, Finance Re: QOTD: Exposure to certain chemicals commonly used in elementary school [#permalink] ### Show Tags 22 Nov 2017, 03:07 souvik101990 wrote: [textarea] Verbal Question of The Day: Day 161: Critical Reasoning Exposure to certain chemicals commonly used in elementary schools as cleaners or pesticides causes allergic reactions in some children. Elementary school nurses in Renston report that the proportion of schoolchildren sent to them for treatment of allergic reactions to those chemicals has increased significantly over the past ten years. Therefore, either Renston's schoolchildren have been exposed to greater quantities of the chemicals, or they are more sensitive to them than schoolchildren were ten years ago. Summary - Nurses assume children are more exposed to chemicals, or more sensitive than children were 10 years ago as the # of cases has increased significantly. Assumption - The likelihood of children sent to the nurse after being exposed is the same as it was 10 years ago. In other words, nothing has changed. Quote: Which of the following is an assumption on which the argument depends? (A) The number of school nurses employed by Renston's elementary schools has not decreased over the past ten years. The number of nurses has decreased over the past ten years. Great, but it has no impact on the conclusion. OUT Quote: (B) Children who are allergic to the chemicals are no more likely than other children to have allergies to other substances. I won't even try an opposite test on this option, as it's irrelevant. OUT! Quote: (C) Children who have allergic reactions to the chemicals are not more likely to be sent to a school nurse now than they were ten years ago. Children who have allergic reactions to the chemicals are MORE LIKELY to be sent to a school nurse than they were ten years ago. If that's the case, it completely destroys the argument's conclusion that students are either more sensitive now, or are more exposed to the chemicals. KEEP! Quote: (D) The chemicals are not commonly used as cleaners or pesticides in houses and apartment buildings in Renston. This option is similar to in other countries blah blah blah happens. We are only concerned with the use of the pesticides and cleaners at the school. TO make this assumption work, we would also have to assume that even though the students were exposed at home, they were sent to the school nurse instead of going to the doctor at a hospital etc. OUT! Quote: (E) Children attending elementary school do not make up a larger proportion of Renston's population now than they did ten years ago. This is irrelevant. OUT! C is the answer IMO. _________________ Put in the work, and that dream score is yours! Manager Joined: 11 Jun 2017 Posts: 80 QOTD: Exposure to certain chemicals commonly used in elementary school [#permalink] ### Show Tags 22 Nov 2017, 05:04 souvik101990 wrote: Verbal Question of The Day: Day 161: Critical Reasoning Subscribe to GMAT Question of the Day: E-mail | RSS For All QOTD Questions Click Here Exposure to certain chemicals commonly used in elementary schools as cleaners or pesticides causes allergic reactions in some children. Elementary school nurses in Renston report that the proportion of schoolchildren sent to them for treatment of allergic reactions to those chemicals has increased significantly over the past ten years. Therefore, either Renston's schoolchildren have been exposed to greater quantities of the chemicals, or they are more sensitive to them than schoolchildren were ten years ago. Which of the following is an assumption on which the argument depends? (A) The number of school nurses employed by Renston's elementary schools has not decreased over the past ten years. (B) Children who are allergic to the chemicals are no more likely than other children to have allergies to other substances. (C) Children who have allergic reactions to the chemicals are not more likely to be sent to a school nurse now than they were ten years ago. (D) The chemicals are not commonly used as cleaners or pesticides in houses and apartment buildings in Renston. (E) Children attending elementary school do not make up a larger proportion of Renston's population now than they did ten years ago. Every question of the day will be followed by an expert reply by GMATNinja in 12-15 hours. Stay tuned! Post your answers and explanations to earn kudos. The argument concludes by stating that the increase in proportion of school children sent to elementary school nurses for treatment of allergic reactions to chemicals might be either because the students have been exposed to greater quantities of the chemicals, or that they are more sensitive to chemicals than schoolchildren were ten years ago. The argument is hence, assuming that these are the only 2 possible reasons for the increased proportion. Thus, we need to find an answer choice that eliminates any alternative reasons. What would cause the conclusion to break down ? - Pointing out an alternative reason. Possible alternatives : 1) What if the number of students has increased over the past ten years ? Then the proportion could be higher without children being more sensitive or being exposed to these chemicals on a greater scale. 2) What if earlier also the magnitude of the reaction was similar but children were not sent to schools then ( ten years ago) probably because it was felt that a treatment is not required, however over the period of ten years more children are being sent to nurses. (A) The number of school nurses employed by Renston's elementary schools has not decreased over the past ten years. - The number of nurses is irrelevant; the argument is talking about the proportion of reported cases here. (B) Children who are allergic to the chemicals are no more likely than other children to have allergies to other substances. - argument talks about allergies to only chemicals and not other substances. (C) Children who have allergic reactions to the chemicals are not more likely to be sent to a school nurse now than they were ten years ago. - Yes, negate this: Children who have allergic reactions to the chemicals are more likely to be sent to a school nurse now than they were ten years ago. This would naturally lead in an increased proportion of students being sent to nurses and this breaks down the conclusion that there can only be two possible reasons. (D) The chemicals are not commonly used as cleaners or pesticides in houses and apartment buildings in Renston. - This is irrelevant. (E) Children attending elementary school do not make up a larger proportion of Renston's population now than they did ten years ago. - The comparison and argument is limited to elementary school children and is nowhere related to the rest of the population. C is correct. BSchool Forum Moderator Joined: 05 Jul 2017 Posts: 439 Location: India GMAT 1: 700 Q49 V36 GPA: 4 QOTD: Exposure to certain chemicals commonly used in elementary school [#permalink] ### Show Tags 28 May 2018, 00:03 - The premise is talking about this ratio $$Total # of students sent / Total # of Students$$. - This has increased. The possible reasons for this are i) Exposure to greater quantities of chemicals ii) They are more sensitive to chemicals now than 10 years before Now lets look at the options. REMEMBER, we need to find an assumption (A) The number of school nurses employed by Renston's elementary schools has not decreased over the past ten years. -->This doesn't affect the ratio in any way. It is not necessary for the argument to hold true. Hence INCORRECT (B) Children who are allergic to the chemicals are no more likely than other children to have allergies to other substances. --> we are not concerned about substances. Hence INCORRECT (C) Children who have allergic reactions to the chemicals are not more likely to be sent to a school nurse now than they were ten years ago. --> Bingo! Lets negate this option. If children are more likely to be sent to school nurse now than they were ten years ago. Then this gives us alternate reason for the increase and weakens the conclusion. Hence CORRECT (D) The chemicals are not commonly used as cleaners or pesticides in houses and apartment buildings in Renston. --> IRRELEVANT and INCORRECT (E) Children attending elementary school do not make up a larger proportion of Renston's population now than they did ten years ago. --> This option doesn't affect the ratio the premise is talking about in anyway. INCORRECT _________________ Intern Joined: 01 Apr 2018 Posts: 1 QOTD: Exposure to certain chemicals commonly used in elementary school [#permalink] ### Show Tags 29 May 2018, 21:43 akshayk wrote: souvik101990 wrote: [textarea] Verbal Question of The Day: Day 161: Critical Reasoning Exposure to certain chemicals commonly used in elementary schools as cleaners or pesticides causes allergic reactions in some children. Elementary school nurses in Renston report that the proportion of schoolchildren sent to them for treatment of allergic reactions to those chemicals has increased significantly over the past ten years. Therefore, either Renston's schoolchildren have been exposed to greater quantities of the chemicals, or they are more sensitive to them than schoolchildren were ten years ago. Summary - Nurses assume children are more exposed to chemicals, or more sensitive than children were 10 years ago as the # of cases has increased significantly. Assumption - The likelihood of children sent to the nurse after being exposed is the same as it was 10 years ago. In other words, nothing has changed. How is this the assumption. The arguments states lementary school nurses in Renston report that the proportion of schoolchildren sent to them for treatment of allergic reactions to those chemicals has increased significantlyover the past ten years. It says proportion of school children sent for treatment has increases significantly. Can you please explain? GMAT Club Verbal Expert Status: GMAT and GRE tutor Joined: 13 Aug 2009 Posts: 1830 Location: United States GMAT 1: 780 Q51 V46 GMAT 2: 800 Q51 V51 GRE 1: Q170 V170 Re: QOTD: Exposure to certain chemicals commonly used in elementary school [#permalink] ### Show Tags 30 May 2018, 16:20 NishiAjmera wrote: akshayk wrote: souvik101990 wrote: [textarea] Verbal Question of The Day: Day 161: Critical Reasoning Exposure to certain chemicals commonly used in elementary schools as cleaners or pesticides causes allergic reactions in some children. Elementary school nurses in Renston report that the proportion of schoolchildren sent to them for treatment of allergic reactions to those chemicals has increased significantly over the past ten years. Therefore, either Renston's schoolchildren have been exposed to greater quantities of the chemicals, or they are more sensitive to them than schoolchildren were ten years ago. Summary - Nurses assume children are more exposed to chemicals, or more sensitive than children were 10 years ago as the # of cases has increased significantly. Assumption - The likelihood of children sent to the nurse after being exposed is the same as it was 10 years ago. In other words, nothing has changed. How is this the assumption. The arguments states lementary school nurses in Renston report that the proportion of schoolchildren sent to them for treatment of allergic reactions to those chemicals has increased significantlyover the past ten years. It says proportion of school children sent for treatment has increases significantly. Can you please explain? I think you are confusing "proportion of schoolchildren" (includes those with and those without allergic reactions) with "proportion of children who have allergic reactions." Yes, "the proportion of schoolchildren sent to nurses for treatment of allergic reactions to those chemicals has increased significantly over the past ten years." I.e. maybe ten years ago only about 10% of school children were sent to the nurse for the allergic reactions, and nowadays about 20% of school children are sent. But that does NOT say anything about the proportion of children who have allergic reactions. For example, maybe ten years, only 50% of children with allergic reactions were sent to the nurse. If THAT proportion has remained relatively constant, then the conclusion makes sense. But what if nowadays nearly 100% of children with allergic reactions are sent to the nurse? That could explain the overall increase in the proportion of schoolchildren being sent to the nurse. I hope that helps! _________________ GMAT Club Verbal Expert | GMAT/GRE tutor @ www.gmatninja.com (Now hiring!) | GMAT blog | Food blog | Notoriously bad at PMs Beginners' guides to GMAT verbal Reading Comprehension | Critical Reasoning | Sentence Correction YouTube LIVE verbal webinars Series 1: Fundamentals of SC & CR | Series 2: Developing a Winning GMAT Mindset SC & CR Questions of the Day (QOTDs), featuring expert explanations All QOTDs | Subscribe via email | RSS Need an expert reply? Hit the request verbal experts' reply button -- and please be specific about your question. Feel free to tag @GMATNinja and @GMATNinjaTwo in your post. Priority is always given to official GMAT questions. Sentence Correction articles & resources How to go from great (760) to incredible (780) on GMAT SC | That "-ing" Word Probably Isn't a Verb | That "-ed" Word Might Not Be a Verb, Either | No-BS Guide to GMAT Idioms | "Being" is not the enemy | WTF is "that" doing in my sentence? Reading Comprehension, Critical Reasoning, and other articles & resources All GMAT Ninja articles on GMAT Club | Using LSAT for GMAT CR & RC |7 reasons why your actual GMAT scores don't match your practice test scores | How to get 4 additional "fake" GMAT Prep tests for$29.99 | Time management on verbal

Re: QOTD: Exposure to certain chemicals commonly used in elementary school &nbs [#permalink] 30 May 2018, 16:20
Display posts from previous: Sort by

# Events & Promotions

 Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.