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

It is currently 21 Aug 2018, 01:29

Close

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
Your Progress

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

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Close

Request Expert Reply

Confirm Cancel

Did at least 15 percent of the children in Springfield suffer adverse

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 48074
Did at least 15 percent of the children in Springfield suffer adverse  [#permalink]

Show Tags

New post 19 Sep 2016, 05:47
2
6
00:00
A
B
C
D
E

Difficulty:

  55% (hard)

Question Stats:

55% (01:06) correct 45% (00:59) wrong based on 148 sessions

HideShow timer Statistics

Did at least 15 percent of the children in Springfield suffer adverse effects after taking a certain vaccination?

(1) Among the Springfield children, 20 percent of the girls and more than 10 percent of the boys suffered adverse effects after taking the vaccination.

(2) Among the Springfield children, 20 percent of the boys and more than 15 percent of the girls suffered adverse effects after taking that vaccination.

_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Most Helpful Expert Reply
CEO
CEO
User avatar
D
Joined: 12 Sep 2015
Posts: 2710
Location: Canada
Re: Did at least 15 percent of the children in Springfield suffer adverse  [#permalink]

Show Tags

New post 19 Sep 2016, 08:02
3
Top Contributor
2
Bunuel wrote:
Did at least 15 percent of the children in Springfield suffer adverse effects after taking a certain vaccination?

(1) Among the Springfield children, 20 percent of the girls and more than 10 percent of the boys suffered adverse effects after taking the vaccination.

(2) Among the Springfield children, 20 percent of the boys and more than 15 percent of the girls suffered adverse effects after taking that vaccination.


Target question: Did at least 15 percent of the children in Springfield suffer adverse effects after taking a certain vaccination?

Statement 1: Among the Springfield children, 20% of the girls and more than 10% of the boys suffered adverse effects after taking the vaccination.
This question tests an important (and often-tested) GMAT concept - weighted averages.

Let's say that 12% of the boys suffered adverse effects.
There are three possible scenarios to consider:
a) IF there were an EQUAL number of boys and girls, then the percentage of all children who suffered adverse effects would equal the average of 12% of 20%. So, the percentage of all children who suffered adverse effects would equal (20% + 12% )/2 = 16%
b) IF there were an MORE girls than boys, then the percentage of all children who suffered adverse effects would be closer to 20% than to 12%
c) IF there were an MORE boys than girls, then the percentage of all children who suffered adverse effects would be closer to 12% than to 20%

Now consider the following CONFLICTING cases
Case a: 20% of the girls suffered adverse effects, and 20% of the boys suffered adverse effects. If there are 2 girls and 2 boys, then 20% of all children suffered adverse effects.
Case b: 20% of the girls suffered adverse effects, and 11% of the boys suffered adverse effects. If there are 2 girls and 1000 boys, then the percentage of all children who suffered adverse effects will be very very close to 11%, since the boys have the bigger influence on the total percentage
Since we cannot answer the target question with certainty, statement 1 is NOT SUFFICIENT

Statement 2: Among the Springfield children, 20 percent of the boys and more than 15 percent of the girls suffered adverse effects after taking that vaccination.
Since both groups (boys and girls) are such that EACH suffered more than 15% , then the COMBINED population is certain to have an adverse rate that's greater than 15%
Since we can answer the target question with certainty, statement 2 is SUFFICIENT

Answer:

RELATED VIDEO

_________________

Brent Hanneson – Founder of gmatprepnow.com

Image

General Discussion
Retired Moderator
avatar
G
Joined: 26 Nov 2012
Posts: 598
Premium Member
Did at least 15 percent of the children in Springfield suffer adverse  [#permalink]

Show Tags

New post 19 Sep 2016, 07:05
Bunuel wrote:
Did at least 15 percent of the children in Springfield suffer adverse effects after taking a certain vaccination?

(1) Among the Springfield children, 20 percent of the girls and more than 10 percent of the boys suffered adverse effects after taking the vaccination.

(2) Among the Springfield children, 20 percent of the boys and more than 15 percent of the girls suffered adverse effects after taking that vaccination.



Stat 1: let x be for boys and y be girls

0.2(y)+ >0.1(x)...we can't say anything from this.

Stat 2: 0.2(x) + > 0.15(y)... since we have information here itself that more than 15 percent of the girls suffered adverse effects... we can say that > 15% of children suffer adverse effects when we club boys information too...I go for B.

IMO option B.
DS Forum Moderator
avatar
P
Joined: 22 Aug 2013
Posts: 1343
Location: India
Premium Member
Re: Did at least 15 percent of the children in Springfield suffer adverse  [#permalink]

Show Tags

New post 04 Dec 2017, 11:04
Bunuel wrote:
Did at least 15 percent of the children in Springfield suffer adverse effects after taking a certain vaccination?

(1) Among the Springfield children, 20 percent of the girls and more than 10 percent of the boys suffered adverse effects after taking the vaccination.

(2) Among the Springfield children, 20 percent of the boys and more than 15 percent of the girls suffered adverse effects after taking that vaccination.



If the total number of people is made up of X and Y (Thus total being X+Y), and we are given an attribute that is shared by a% of these X people, and b% of these y people, and we are asked what is the overall % of people (out of total X+Y) who share this attribute, then that % will always be between a and b. So overall % in these cases will be somewhere between the two. Now if value of X is more than Y, answer will be closer to a, and vice-versa. This is a concept of weighted average and can be applied in this question.

(1) We dont know how many girls are there and how many boys are there. But since this effect is present in 20% of girls and more than 10% of boys, overall percent children with this effect would lie somewhere between 10% and 20%. If the number of girls is more than boys, children affected would be more than 15%, but if number of boys is more, it could be less than 15% (we dont even know whats the exact percentage of boys affected). So Insufficient.

(2) 20% of boys affected, more than 15% of girls affected. By same concept, overall children affected would be somewhere between 20% and 15%, thus more than 15% definitely. Sufficient.

Hence B answer
Re: Did at least 15 percent of the children in Springfield suffer adverse &nbs [#permalink] 04 Dec 2017, 11:04
Display posts from previous: Sort by

Did at least 15 percent of the children in Springfield suffer adverse

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  

Events & Promotions

PREV
NEXT


GMAT Club MBA Forum Home| About| Terms and Conditions and Privacy Policy| GMAT Club Rules| Contact| Sitemap

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®.