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

It is currently 15 Aug 2018, 21:18

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

A woman has seven cookies - four chocolate chip and three

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

Hide Tags

Director
Director
User avatar
Joined: 07 Jun 2004
Posts: 604
Location: PA
A woman has seven cookies - four chocolate chip and three  [#permalink]

Show Tags

New post Updated on: 18 Sep 2012, 06:03
8
16
00:00
A
B
C
D
E

Difficulty:

  95% (hard)

Question Stats:

53% (01:41) correct 47% (02:12) wrong based on 292 sessions

HideShow timer Statistics

A woman has seven cookies - four chocolate chip and three oatmeal. She gives one cookie to each of her six children: Nicole, Ronit, Kim, Deborah, Mark, and Terrance. If Deborah will only eat the kind of cookie that Kim eats, in how many different ways can the cookies be distributed?

(A) 5040
(B) 50
(C) 25
(D) 15
(E) 12

_________________

If the Q jogged your mind do Kudos me : )


Originally posted by rxs0005 on 06 Feb 2011, 15:37.
Last edited by Bunuel on 18 Sep 2012, 06:03, edited 1 time in total.
Edited the question.
Most Helpful Expert Reply
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 47920
Re: Combinations cookie problem  [#permalink]

Show Tags

New post 06 Feb 2011, 15:49
13
15
rxs0005 wrote:
A woman has seven cookies--four chocolate chip and three oatmeal. She gives one cookie to each of her six children: Nicole, Ronit, Kim, Deborah, Mark, and Terrance. If Deborah will only eat the kind of cookie that Kim eats, in how many different ways can the cookies be distributed?

(A) 5040
(B) 50
(C) 25
(D) 15
(E) 12


We have to distribute 7 cookies between 6 kids and give 7th leftover cookie for charity, so distribute 7 cookies between 7 entities: Deborah, Kim, 1, 2, 3, 4, 5.

If Deborah and Kim get chocolate cookies then there will be 2 chocolate and 3 oatmeal cookies to distribute between 5: 5!/(2!3!) = 10 (assign 5 cookies out of which 2 chocolate and 3 oatmeal cookies are identical to 5 people);

If Deborah and Kim get oatmeal cookies then there will be 4 chocolate and 1 oatmeal cookie to distribute between 5: 5!/(4!1!) = 5;

10 + 5 = 15.

Answer: D.
_________________

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

General Discussion
Director
Director
User avatar
Joined: 07 Jun 2004
Posts: 604
Location: PA
Re: Combinations cookie problem  [#permalink]

Show Tags

New post 06 Feb 2011, 16:07
Bunuel

thanks for the explanation , my Q is why do we divide 5! by 3! and 2! (because of the repeatsi assume) can you explain that conceptually i know i am missing something fundamental here

my Q is why do we do that or how do we get to 5C2 without that line of reasoning if its there at all...

thanks
_________________

If the Q jogged your mind do Kudos me : )

Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 47920
Re: Combinations cookie problem  [#permalink]

Show Tags

New post 06 Feb 2011, 16:10
rxs0005 wrote:
Bunuel

thanks for the explanation , my Q is why do we divide 5! by 3! and 2! (because of the repeatsi assume) can you explain that conceptually i know i am missing something fundamental here

my Q is why do we do that or how do we get to 5C2 without that line of reasoning if its there at all...

thanks


This might help: counting-ps-106762.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

Retired Moderator
avatar
B
Joined: 17 Sep 2013
Posts: 369
Concentration: Strategy, General Management
GMAT 1: 730 Q51 V38
WE: Analyst (Consulting)
GMAT ToolKit User Premium Member Reviews Badge
Re: A woman has seven cookies - four chocolate chip and three  [#permalink]

Show Tags

New post 24 Apr 2014, 01:35
AM I conceptually correct when I say that 5c4 is the number of ways to choose 4 cookies out of 5 (As we have 4 children)...and then the cookies will arrange themselves among children in 4! ways
Of the cookies 3 are identical and other 2 are identical
So---> 5c4*4!/3!*2! = 10

Will this rule apply even when the cookies are 10 and the children are 4...or is it applicable coincidentally for this very specific question
_________________

Appreciate the efforts...KUDOS for all
Don't let an extra chromosome get you down..:P

Intern
Intern
avatar
Joined: 01 Mar 2015
Posts: 48
Re: A woman has seven cookies - four chocolate chip and three  [#permalink]

Show Tags

New post 11 Oct 2015, 08:57
1
Bunuel wrote:
rxs0005 wrote:
A woman has seven cookies--four chocolate chip and three oatmeal. She gives one cookie to each of her six children: Nicole, Ronit, Kim, Deborah, Mark, and Terrance. If Deborah will only eat the kind of cookie that Kim eats, in how many different ways can the cookies be distributed?

(A) 5040
(B) 50
(C) 25
(D) 15
(E) 12


We have to distribute 7 cookies between 6 kids and give 7th leftover cookie for charity, so distribute 7 cookies between 7 entities: Deborah, Kim, 1, 2, 3, 4, 5.

If Deborah and Kim get chocolate cookies then there will be 2 chocolate and 3 oatmeal cookies to distribute between 5: 5!/(2!3!) = 10 (assign 5 cookies out of which 2 chocolate and 3 oatmeal cookies are identical to 5 people);

If Deborah and Kim get oatmeal cookies then there will be 4 chocolate and 1 oatmeal cookie to distribute between 5: 5!/(4!1!) = 5;

10 + 5 = 15.

Answer: D.


the approach to consider 7th left over cookie for charity is good
it helped me to cut down time for question solving
Intern
Intern
avatar
B
Joined: 01 Jul 2018
Posts: 9
Re: A woman has seven cookies - four chocolate chip and three  [#permalink]

Show Tags

New post 25 Jul 2018, 08:42
Hi Bunuel

The reason you don't multiply each part by 5C2 and 3C2 to choose which 2 cookies to give Deborah and Kim is because cookies identical?

Bunuel wrote:
rxs0005 wrote:
A woman has seven cookies--four chocolate chip and three oatmeal. She gives one cookie to each of her six children: Nicole, Ronit, Kim, Deborah, Mark, and Terrance. If Deborah will only eat the kind of cookie that Kim eats, in how many different ways can the cookies be distributed?

(A) 5040
(B) 50
(C) 25
(D) 15
(E) 12


We have to distribute 7 cookies between 6 kids and give 7th leftover cookie for charity, so distribute 7 cookies between 7 entities: Deborah, Kim, 1, 2, 3, 4, 5.

If Deborah and Kim get chocolate cookies then there will be 2 chocolate and 3 oatmeal cookies to distribute between 5: 5!/(2!3!) = 10 (assign 5 cookies out of which 2 chocolate and 3 oatmeal cookies are identical to 5 people);

If Deborah and Kim get oatmeal cookies then there will be 4 chocolate and 1 oatmeal cookie to distribute between 5: 5!/(4!1!) = 5;

10 + 5 = 15.

Answer: D.
Re: A woman has seven cookies - four chocolate chip and three &nbs [#permalink] 25 Jul 2018, 08:42
Display posts from previous: Sort by

A woman has seven cookies - four chocolate chip and three

  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®.