It is currently 24 Feb 2018, 13:39

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

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

Are at least 20% of the people in City H who are at least 30

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

Hide Tags

1 KUDOS received
Intern
Intern
avatar
Joined: 23 May 2011
Posts: 1
Are at least 20% of the people in City H who are at least 30 [#permalink]

Show Tags

New post 11 Aug 2011, 06:28
1
This post received
KUDOS
3
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  75% (hard)

Question Stats:

48% (01:21) correct 52% (01:56) wrong based on 105 sessions

HideShow timer Statistics

Are at least 20% of the people in City H who are at least 30 years old bilingual?

1. In City H, 25 percent of the bilingual population is at least 30 years old.
2. In City H, of the population at least 30 years old, 18 percent of the women and 17 percent of the men are bilingual.
[Reveal] Spoiler: OA
Senior Manager
Senior Manager
User avatar
Joined: 03 Mar 2010
Posts: 413
Schools: Simon '16 (M)
Re: DS percents Question from Kaplan GMAT [#permalink]

Show Tags

New post 11 Aug 2011, 11:00
anjanapadmaraj4 wrote:
Are at least 20% of the people in City H who are at least 30 years old bilingual?

1. In City H, 25 percent of the bilingual population is at least 30 years old.
2. In City H, of the population at least 30 years old, 18 percent of the women and 17 percent of the men are bilingual.


Question: Are at least 20% of the people in City H who are at least 30 years old bilingual?
or What is the population of people who are at least 30 years old?

Stmt1: In City H, 25 percent of the bilingual population is at least 30 years old.
Let the population of Bilingual be = 100
Then, 25% of Bilingual population (100) is atleast 30yrs old.
i.e 25*100/100 = 25 people are bilingual and atleast 30 yrs old.

Now, is 20% of x (population of people who are at least 30 years old) = 25
or is x= 125? We do not know. Insufficient.

Stmt2: In City H, of the population at least 30 years old, 18 percent of the women and 17 percent of the men are bilingual
Let the population of people atleast 30 yrs old be 100
Bilingual Population:
18 percent of the women and 17 percent of the men are bilingual= 0.18*100+0.17*100=35

20% of people in City H who are atleast 30 years old =0.2*100=20
We can see that number of people who are 30 yrs old and bilingual is 35% which is greater than 20%
Sufficient.

OA B.
_________________

My dad once said to me: Son, nothing succeeds like success.

Manager
Manager
avatar
Joined: 15 Feb 2011
Posts: 240
Re: DS percents Question from Kaplan GMAT [#permalink]

Show Tags

New post 12 Aug 2011, 11:36
fluke wrote:
anjanapadmaraj4 wrote:
Are at least 20% of the people in City H who are at least 30 years old bilingual?

1. In City H, 25 percent of the bilingual population is at least 30 years old.

CaseI: (100 People)
4 Bilingual: 1 at least 30, 3 less than 30
96 Not-Bilingual: 96 at least 30, 0 less than 30
% of at least 30 who are bilingual=1/(96+1)<20%

CaseII: (100 People)
4 Bilingual: 1 at least 30, 3 less than 30
96 Not-Bilingual: 0 at least 30, 96 less than 30
% of at least 30 who are bilingual=1/1=100%>20%

Not Sufficient.


2. In City H, of the population at least 30 years old, 18 percent of the women and 17 percent of the men are bilingual.

Irrespective of the % of population that is at least 30, we know for sure the percent of bilingual will always be < 20 because cumulative % of men(18) and women(17) is < 20

Sufficient.




Fluke, pls I need help here..

Stmt1: In City H, 25 percent of the bilingual population is at least 30 years old.
Let the population of Bilingual be = 100
Then, 25% of Bilingual population (100) is atleast 30yrs old.
i.e 25*100/100 = 25 people are bilingual and atleast 30 yrs old.

Now,20% of x (population of people who are at least 30 years old) = 25
so x= 125...as we have the total population and no of ppl bilingual and atleast 30..we can find if it's at least 20%...isn't that sufficient?? what am i missing

Also, is there a simple way to explain statement2
Senior Manager
Senior Manager
User avatar
Joined: 03 Mar 2010
Posts: 413
Schools: Simon '16 (M)
Re: DS percents Question from Kaplan GMAT [#permalink]

Show Tags

New post 12 Aug 2011, 12:38
DeeptiM wrote:
Stmt1: In City H, 25 percent of the bilingual population is at least 30 years old.
Let the population of Bilingual be = 100
Then, 25% of Bilingual population (100) is atleast 30yrs old.
i.e 25*100/100 = 25 people are bilingual and atleast 30 yrs old.

Now,20% of x (population of people who are at least 30 years old) = 25
so x= 125...as we have the total population and no of ppl bilingual and atleast 30..we can find if it's at least 20%...isn't that sufficient?? what am i missing


Take population of bilingual to be 1000.
x will be 1250. hence population of people who are atleast 30 years old really depends upon what you assume population of bilingual to be.
_________________

My dad once said to me: Son, nothing succeeds like success.

Manager
Manager
avatar
Joined: 28 May 2011
Posts: 190
Location: United States
Concentration: General Management, International Business
GMAT 1: 720 Q49 V38
GPA: 3.6
WE: Project Management (Computer Software)
Re: DS percents Question from Kaplan GMAT [#permalink]

Show Tags

New post 12 Aug 2011, 18:30
jamifahad wrote:
anjanapadmaraj4 wrote:
Are at least 20% of the people in City H who are at least 30 years old bilingual?

Stmt2: In City H, of the population at least 30 years old, 18 percent of the women and 17 percent of the men are bilingual
Let the population of people atleast 30 yrs old be 100
Bilingual Population:
18 percent of the women and 17 percent of the men are bilingual= 0.18*100+0.17*100=35

20% of people in City H who are atleast 30 years old =0.2*100=20
We can see that number of people who are 30 yrs old and bilingual is 35% which is greater than 20%
Sufficient.

OA B.


I think there is some problem in the red part of the calculation

if there are 100 people atleast 30 years or old, than you can't have 100 men and 100 women.

So let;s take two cases

a> Men = 50, Women = 50
than total# of bilungual people = 0.18*50+0.17*50 = 9 + 8.5 = approx. 18 (that is less than 20)

b> Men = 70, Women = 30
than total# of bilungual people = 0.18*70+0.17*30 = 13 + 6 = approx. 19 (that is less than 20)


So with the assumption, that there are only Male and Female in the city demography, B is sufficient.
_________________

-------------------------------------------------------------------------------------------------------------------------------
http://gmatclub.com/forum/a-guide-to-the-official-guide-13-for-gmat-review-134210.html
-------------------------------------------------------------------------------------------------------------------------------

Math Forum Moderator
avatar
Joined: 20 Dec 2010
Posts: 1945
Re: DS percents Question from Kaplan GMAT [#permalink]

Show Tags

New post 13 Aug 2011, 01:48
DeeptiM wrote:
Fluke, pls I need help here..

Stmt1: In City H, 25 percent of the bilingual population is at least 30 years old.
Let the population of Bilingual be = 100
Then, 25% of Bilingual population (100) is at least 30yrs old.
i.e 25*100/100 = 25 people are bilingual and at least 30 yrs old.

Now,20% of x (population of people who are at least 30 years old) = 25
so x= 125...
as we have the total population and no of ppl bilingual and atleast 30..we can find if it's at least 20%...isn't that sufficient?? what am i missing

Also, is there a simple way to explain statement2


I actually didn't get how you got the red part above.

Q: If there are x people who are at least 30, how many of them are bilingual?

1. In City H, 25 percent of the bilingual population is at least 30 years old.

It says just the reverse;
25% of bilinguals are at least 30.

Now, we know neither the total population nor the number of people who are at least 30. We just know that if there are 100 bilinguals among the people in H, 25 of those are at least 30 AND thus, 75 of those are less than 30.

CASE I:
Now, we take non-bilingual into account:
If there are 900 non-bilingual; out of those 900, all are less than 30 AND 0 person or none is at least 30.

Then
Total Population=Bilingual+Non-bilingual=100+900=1000
People who are at least 30= At least 30 among Bilinguals+At least 30 among non-Bilinguals=25+0=25

People who are at least 30= 25
People who are at least 30 AND bilinguals= 25
%=25/25=100%>20%

CASE II:
But, if
If there are 900 non-bilingual; out of those 900, none is less than 30 AND 900 people are at least 30.

Then
Total Population=Bilingual+Non-bilingual=100+900=1000
People who are at least 30= At least 30 among Bilinguals+At least 30 among non-Bilinguals=25+900=25

People who are at least 30= 925
People who are at least 30 AND bilinguals= 25
%=25/925= much less than 20%

We saw two cases:
First, in which % of bilinguals amongst people who are at least 30=100%
Second, in which % of bilinguals amongst people who are at least 30 less than 20%

So, just by knowing that "25 percent of the bilingual population is at least 30 years old" is NOT enough to find whether "at least 20% of the people in City H who are at least 30 years old bilingual". Because, we don't know what's the population, how many are at least 30 etc...

Not Sufficient.

2. In City H, of the population at least 30 years old, 18 percent of the women and 17 percent of the men are bilingual.

Here, we are given ready-made what's been asked. Out of people who are at least 30; 18% bilingual women and 17% bilingual men.

No matter how many people are at least 30 year old; the % of bilinguals(men+women) will always be less than 20; because neither % of men is more than 20 nor that of women is.

e.g.
100 people out of 1million are at least 30.
Out of 100: 90 Men, 10 Women
(0.18*90+0.17*10) will always be less than 0.2(90+10)

x Men, y Women
0.18x+0.17y< 0.2x+0.2y=0.2(x+y)
Sufficient.

Ans: "B"
_________________

~fluke

GMAT Club Premium Membership - big benefits and savings

Manager
Manager
avatar
Joined: 15 Feb 2011
Posts: 240
Re: DS percents Question from Kaplan GMAT [#permalink]

Show Tags

New post 13 Aug 2011, 06:13
whoa..good explanation..+1 to you Fluke

Lemme digest it..will get back to you in case required..hehe
Senior Manager
Senior Manager
User avatar
Status: mba here i come!
Joined: 07 Aug 2011
Posts: 260
GMAT ToolKit User
Re: DS percents Question from Kaplan GMAT [#permalink]

Show Tags

New post 01 Sep 2011, 08:25
2) % of both male & female who are 30yrs old bilingual< 20%.
this % can never be more than 20%. if males are less than 20%, then females have to be more than 20% to cover up.

no need to do any calculation.
_________________

press +1 Kudos to appreciate posts
Download Valuable Collection of Percentage Questions (PS/DS)

Expert Post
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 43896
Re: Are at least 20% of the people in City H who are at least 30 [#permalink]

Show Tags

New post 17 May 2016, 05:43
anjanapadmaraj4 wrote:
Are at least 20% of the people in City H who are at least 30 years old bilingual?

1. In City H, 25 percent of the bilingual population is at least 30 years old.
2. In City H, of the population at least 30 years old, 18 percent of the women and 17 percent of the men are bilingual.


Similar question to practice: are-at-least-10-percent-of-the-people-in-country-x-who-are-122734.html
_________________

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

Non-Human User
User avatar
Joined: 09 Sep 2013
Posts: 13759
Premium Member
Re: Are at least 20% of the people in City H who are at least 30 [#permalink]

Show Tags

New post 31 Jan 2018, 08:20
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________

GMAT Books | GMAT Club Tests | Best Prices on GMAT Courses | GMAT Mobile App | Math Resources | Verbal Resources

Re: Are at least 20% of the people in City H who are at least 30   [#permalink] 31 Jan 2018, 08:20
Display posts from previous: Sort by

Are at least 20% of the people in City H who are at least 30

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


cron

GMAT Club MBA Forum Home| About| Terms and Conditions| 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®.