Find all School-related info fast with the new School-Specific MBA Forum

It is currently 22 Sep 2014, 22:20

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.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

Lake A has a duck population of 30 females and 36 males.

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
2 KUDOS received
Intern
Intern
avatar
Joined: 28 Aug 2012
Posts: 21
Location: United States
Concentration: General Management, Leadership
Schools: Thunderbird '16
GPA: 3.37
WE: Information Technology (Consulting)
Followers: 1

Kudos [?]: 23 [2] , given: 6

GMAT ToolKit User
Lake A has a duck population of 30 females and 36 males. [#permalink] New post 25 May 2013, 14:27
2
This post received
KUDOS
00:00
A
B
C
D
E

Difficulty:

  45% (medium)

Question Stats:

62% (02:21) correct 38% (01:04) wrong based on 119 sessions
Lake A has a duck population of 30 females and 36 males. Lake B’s duck population consists of the same ratio of females to males. If 6 new female ducks are added to Lake B and no other ducks are added or removed, the new total duck population of Lake B could be which of the following?

A. 144
B. 105
C. 78
D. 51
E. 36
[Reveal] Spoiler: OA
Expert Post
7 KUDOS received
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 22969
Followers: 3516

Kudos [?]: 26706 [7] , given: 2714

Re: Lake A has a duck population of 30 females and 36 males. [#permalink] New post 25 May 2013, 14:34
7
This post received
KUDOS
Expert's post
yogirb8801 wrote:
Lake A has a duck population of 30 females and 36 males. Lake B’s duck population consists of the same ratio of females to males. If 6 new female ducks are added to Lake B and no other ducks are added or removed, the new total duck population of Lake B could be which of the following?

A. 144
B. 105
C. 78
D. 51
E. 36


The ratio of females to males in Lake B is 30:36 = 5:6 --> the total number of ducks in Lake B must be a multiple of (5+6)=11.

When 6 new female ducks are added to Lake B, the total number of ducks in Lake B becomes a multiple of 11 plus 6.

Only 105 is a multiple of 11 plus 6: 9*11+6=105.

Answer: B.

Hope it's clear.
_________________

NEW TO MATH FORUM? PLEASE READ THIS: ALL YOU NEED FOR QUANT!!!

PLEASE READ AND FOLLOW: 11 Rules for Posting!!!

RESOURCES: [GMAT MATH BOOK]; 1. Triangles; 2. Polygons; 3. Coordinate Geometry; 4. Factorials; 5. Circles; 6. Number Theory; 7. Remainders; 8. Overlapping Sets; 9. PDF of Math Book; 10. Remainders; 11. GMAT Prep Software Analysis NEW!!!; 12. SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) NEW!!!; 12. Tricky questions from previous years. NEW!!!;

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?
25 extra-hard Quant Tests

Get the best GMAT Prep Resources with GMAT Club Premium Membership

Expert Post
1 KUDOS received
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 22969
Followers: 3516

Kudos [?]: 26706 [1] , given: 2714

Re: Lake A has a duck population of 30 females and 36 males. [#permalink] New post 25 May 2013, 14:46
1
This post received
KUDOS
Expert's post
yogirb8801 wrote:
Lake A has a duck population of 30 females and 36 males. Lake B’s duck population consists of the same ratio of females to males. If 6 new female ducks are added to Lake B and no other ducks are added or removed, the new total duck population of Lake B could be which of the following?

A. 144
B. 105
C. 78
D. 51
E. 36


Similar questions to practice:
bag-a-contains-red-white-and-blue-marbles-such-that-the-red-to-127477.html
the-ratio-of-cupcakes-to-children-at-a-particular-birthday-143833.html
in-a-certain-school-the-ratio-of-boys-to-girls-is-5-to-139469.html
at-a-party-there-were-five-times-as-many-females-as-males-2488.html
some-of-the-people-in-town-x-are-left-handed-some-are-tall-87642.html

Hope it helps.
_________________

NEW TO MATH FORUM? PLEASE READ THIS: ALL YOU NEED FOR QUANT!!!

PLEASE READ AND FOLLOW: 11 Rules for Posting!!!

RESOURCES: [GMAT MATH BOOK]; 1. Triangles; 2. Polygons; 3. Coordinate Geometry; 4. Factorials; 5. Circles; 6. Number Theory; 7. Remainders; 8. Overlapping Sets; 9. PDF of Math Book; 10. Remainders; 11. GMAT Prep Software Analysis NEW!!!; 12. SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) NEW!!!; 12. Tricky questions from previous years. NEW!!!;

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?
25 extra-hard Quant Tests

Get the best GMAT Prep Resources with GMAT Club Premium Membership

Intern
Intern
avatar
Joined: 28 Aug 2012
Posts: 21
Location: United States
Concentration: General Management, Leadership
Schools: Thunderbird '16
GPA: 3.37
WE: Information Technology (Consulting)
Followers: 1

Kudos [?]: 23 [0], given: 6

GMAT ToolKit User
Re: Lake A has a duck population of 30 females and 36 males. [#permalink] New post 27 May 2013, 03:18
Thanks Bunuel for explanation. very helpful.
1 KUDOS received
Intern
Intern
avatar
Joined: 20 Apr 2013
Posts: 10
Followers: 0

Kudos [?]: 4 [1] , given: 0

Re: Lake A has a duck population of 30 females and 36 males. [#permalink] New post 29 May 2013, 08:32
1
This post received
KUDOS
the ratio is 5:6
So let the female ducks be 5x and male be 6x.
Total duck=11x
Now 11x+6 should divide one of the options.
105-6=99
Therefore ans is B
Manager
Manager
User avatar
Joined: 24 Nov 2012
Posts: 162
Concentration: Sustainability, Entrepreneurship
Schools: IMD '16
GMAT 1: 770 Q50 V44
WE: Business Development (Internet and New Media)
Followers: 18

Kudos [?]: 87 [0], given: 73

Re: Lake A has a duck population of 30 females and 36 males. [#permalink] New post 31 May 2013, 12:40
I wrote a table down as following and checked which values could be plugged in

F. M. F+m+6
15 18 38
30 36 71
45 54 105 <--- stopped here
60 72
_________________

You've been walking the ocean's edge, holding up your robes to keep them dry. You must dive naked under, and deeper under, a thousand times deeper! - Rumi

http://www.manhattangmat.com/blog/index ... nprep-com/ - This is worth its weight in gold

Economist GMAT Test - 730, Q50, V41 Aug 9th, 2013
Manhattan GMAT Test - 670, Q45, V36 Aug 11th, 2013
Manhattan GMAT Test - 680, Q47, V36 Aug 17th, 2013
GmatPrep CAT 1 - 770, Q50, V44 Aug 24th, 2013
Manhattan GMAT Test - 690, Q45, V39 Aug 30th, 2013
Manhattan GMAT Test - 710, Q48, V39 Sep 13th, 2013
GmatPrep CAT 2 - 740, Q49, V41 Oct 6th, 2013

GMAT - 770, Q50, V44, Oct 7th, 2013
My Debrief - from-the-ashes-thou-shall-rise-770-q-50-v-44-awa-5-ir-162299.html#p1284542

Intern
Intern
avatar
Joined: 29 Jun 2013
Posts: 5
Followers: 0

Kudos [?]: 0 [0], given: 0

Re: Lake A has a duck population of 30 females and 36 males. [#permalink] New post 17 Aug 2013, 18:52
Why not a multiple of 17?
5 F to 6 M. If you add 6 F then 11 F to 6 M for a total of 17 ducks. So Lake B must have a multiple of 17 ducks?

How can it be a multiple of 11 if you add only female ducks? Once you add 6 female ducks, the ratio of F and M ducks changes!
Senior Manager
Senior Manager
User avatar
Joined: 17 Dec 2012
Posts: 395
Location: India
Followers: 13

Kudos [?]: 182 [0], given: 10

Re: Lake A has a duck population of 30 females and 36 males. [#permalink] New post 17 Aug 2013, 19:20
manavkhurana wrote:
Why not a multiple of 17?
5 F to 6 M. If you add 6 F then 11 F to 6 M for a total of 17 ducks. So Lake B must have a multiple of 17 ducks?

How can it be a multiple of 11 if you add only female ducks? Once you add 6 female ducks, the ratio of F and M ducks changes!


Hi,

The female to male population is in the ratio 5:6. So the total duck population is 11x . It could be 11, 22 ,33 and so on. Now 6 female ducks are added to this population . In other words you are adding 6 to a multiple of 11. So the new duck population should be multiple of 11 + 6.

So the only choice that satisfies this requirement is 105 which is 99+6.

It is not a multiple of 17 because we do not have 11 female ducks for every 6 male ducks.
_________________

Srinivasan Vaidyaraman
Sravna Test Prep
http://www.sravna.com/courses.php

Classroom Courses in Chennai
Online and Correspondence Courses

Intern
Intern
avatar
Joined: 29 Jun 2013
Posts: 5
Followers: 0

Kudos [?]: 0 [0], given: 0

Re: Lake A has a duck population of 30 females and 36 males. [#permalink] New post 17 Aug 2013, 19:37
Got it, thanks a lot!

Basically, as you stated, we are just adding 6 ducks to the original amount of ducks in lake B. If it was a multiple of 17, there would be a lot more than 6 ducks added. We do not have 11 F per 5 M, we just have 6 more ducks overall.

Thanks again.
Manager
Manager
avatar
Joined: 30 May 2013
Posts: 193
Location: India
Concentration: Entrepreneurship, General Management
GPA: 3.82
Followers: 0

Kudos [?]: 27 [0], given: 72

GMAT ToolKit User
Re: Lake A has a duck population of 30 females and 36 males. [#permalink] New post 18 Aug 2013, 18:36
Bunuel wrote:
yogirb8801 wrote:
Lake A has a duck population of 30 females and 36 males. Lake B’s duck population consists of the same ratio of females to males. If 6 new female ducks are added to Lake B and no other ducks are added or removed, the new total duck population of Lake B could be which of the following?

A. 144
B. 105
C. 78
D. 51
E. 36


The ratio of females to males in Lake B is 30:36 = 5:6 --> the total number of ducks in Lake B must be a multiple of (5+6)=11.

When 6 new female ducks are added to Lake B, the total number of ducks in Lake B becomes a multiple of 11 plus 6.

Only 105 is a multiple of 11 plus 6: 9*11+6=105.

Answer: B.

Hope it's clear.


Hi,

I am not able to understand the question properly.

Q says the Lake population is 30 females and 36 males. and for Lake B population the Ratio of male to female is is same. i.e. 3:3.

its nowhere mentioned as Lake B population is of same ratio as Lake A.

please clarify mine plz.

Regards,
Rrsnathan.
Expert Post
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 22969
Followers: 3516

Kudos [?]: 26706 [0], given: 2714

Re: Lake A has a duck population of 30 females and 36 males. [#permalink] New post 19 Aug 2013, 00:46
Expert's post
rrsnathan wrote:
Bunuel wrote:
yogirb8801 wrote:
Lake A has a duck population of 30 females and 36 males. Lake B’s duck population consists of the same ratio of females to males. If 6 new female ducks are added to Lake B and no other ducks are added or removed, the new total duck population of Lake B could be which of the following?

A. 144
B. 105
C. 78
D. 51
E. 36


The ratio of females to males in Lake B is 30:36 = 5:6 --> the total number of ducks in Lake B must be a multiple of (5+6)=11.

When 6 new female ducks are added to Lake B, the total number of ducks in Lake B becomes a multiple of 11 plus 6.

Only 105 is a multiple of 11 plus 6: 9*11+6=105.

Answer: B.

Hope it's clear.


Hi,

I am not able to understand the question properly.

Q says the Lake population is 30 females and 36 males. and for Lake B population the Ratio of male to female is is same. i.e. 3:3.

its nowhere mentioned as Lake B population is of same ratio as Lake A.

please clarify mine plz.

Regards,
Rrsnathan.


Please read the questions carefully:

Lake A has a duck population of 30 females and 36 males --> the ratio is F:M = 30:36 = 5:6.
Lake B’s duck population consists of the same ratio of females to males --> F:M = 5:6.
_________________

NEW TO MATH FORUM? PLEASE READ THIS: ALL YOU NEED FOR QUANT!!!

PLEASE READ AND FOLLOW: 11 Rules for Posting!!!

RESOURCES: [GMAT MATH BOOK]; 1. Triangles; 2. Polygons; 3. Coordinate Geometry; 4. Factorials; 5. Circles; 6. Number Theory; 7. Remainders; 8. Overlapping Sets; 9. PDF of Math Book; 10. Remainders; 11. GMAT Prep Software Analysis NEW!!!; 12. SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) NEW!!!; 12. Tricky questions from previous years. NEW!!!;

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?
25 extra-hard Quant Tests

Get the best GMAT Prep Resources with GMAT Club Premium Membership

Re: Lake A has a duck population of 30 females and 36 males.   [#permalink] 19 Aug 2013, 00:46
    Similar topics Author Replies Last post
Similar
Topics:
1 Each of the 30 students in a class is either male or female Shawshank 2 29 Sep 2012, 23:03
6 Experts publish their posts in the topic Each of the 30 students in a class is either male or female, powerka 6 21 Sep 2009, 17:32
6 male and 8 female employees. A group has to be formed bmwhype2 3 22 Oct 2007, 07:16
A population of game ducks at a western lake contains 55 eyunni 9 09 Oct 2007, 16:33
a club has 8 male and 8 female members. the club is choosing christoph 22 02 Mar 2005, 14:21
Display posts from previous: Sort by

Lake A has a duck population of 30 females and 36 males.

  Question banks Downloads My Bookmarks Reviews Important topics  


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

Powered by phpBB © phpBB Group and phpBB SEO

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®.