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

It is currently 21 Oct 2014, 07:44

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

A certain bakery ran a promotion code: a customer can buy x

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
3 KUDOS received
Manager
Manager
avatar
Joined: 12 Oct 2011
Posts: 133
GMAT 1: 700 Q48 V37
GMAT 2: 720 Q48 V40
Followers: 3

Kudos [?]: 66 [3] , given: 23

A certain bakery ran a promotion code: a customer can buy x [#permalink] New post 04 Apr 2012, 04:47
3
This post received
KUDOS
1
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  75% (hard)

Question Stats:

61% (03:57) correct 39% (02:40) wrong based on 58 sessions
A certain bakery ran a promotion code: a customer can buy x donuts for the regular price of $15 total and get 3 donuts free. If the donut price per dozen during the promotion is $2 less than the normal donut price per dozen, what is x?

A. 15
B. 18
C. 21
D. 25
E. 30
[Reveal] Spoiler: OA
Expert Post
4 KUDOS received
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 23351
Followers: 3604

Kudos [?]: 28710 [4] , given: 2815

Re: A certain bakery ran a promotion code: a customer can buy x [#permalink] New post 04 Apr 2012, 05:07
4
This post received
KUDOS
Expert's post
BN1989 wrote:
A certain bakery ran a promotion code: a customer can buy x donuts for the regular price of $15 total and get 3 donuts free. If the donut price per dozen during the promotion is $2 less than the normal donut price per dozen, what is x?

A. 15
B. 18
C. 21
D. 25
E. 30


The promotion price per donut is \frac{15}{x+3}, thus the promotion price per dozen is 12*\frac{15}{x+3};

The regular price per donut is \frac{15}{x}, thus the regular price per dozen is 12*\frac{15}{x};

We are told that the promotion price per dozen is $2 less than the normal donut price per dozen: 12*\frac{15}{x+3}+2=12*\frac{15}{x} --> \frac{180}{x+3}+2=\frac{180}{x}.

At this point it's better to substitute the values rather than solve for x. Answer choice A, 15, works.

Answer: A.
_________________

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
2 KUDOS received
Veritas Prep GMAT Instructor
User avatar
Joined: 16 Oct 2010
Posts: 4877
Location: Pune, India
Followers: 1152

Kudos [?]: 5348 [2] , given: 165

Re: A certain bakery ran a promotion code: a customer can buy x [#permalink] New post 15 Jan 2013, 19:42
2
This post received
KUDOS
Expert's post
BN1989 wrote:
A certain bakery ran a promotion code: a customer can buy x donuts for the regular price of $15 total and get 3 donuts free. If the donut price per dozen during the promotion is $2 less than the normal donut price per dozen, what is x?

A. 15
B. 18
C. 21
D. 25
E. 30


Responding to a pm:

The wording of the question is such that it is normal to read it twice to understand it well.

Promotion Code: a customer can buy x donuts for the regular price of $15 total and get 3 donuts free

This tells us two things:
The regular price of x donuts is $15. So regular price per donut is 15/x
In the promotion, you get 3 donuts free with x donuts. So promotion price per donut is 15/(x+3)

For a dozen, the promotion price is $2 less. So per donut, the promotion price is $2/12 less.

15/x - 2/12 = 15/(x+3)

Now try to plug in values of x from the options.
The equation holds if x = 15

If you face problems making equations in word problems, the issue is practice. You might struggle with 50 advanced word problem questions but then, when you go on to question no. 51, the equation will be more intuitive. Also, don't give up too soon while trying to solve a question (not talking about the actual or simulated tests here). Put in a good 10-15 mins to figure it out on your own before you finally give up and check out the solution. If you are able to solve it on your own, it will give you insight you will never forget.
To practice advanced word problems, you can check out the Veritas advanced word problems book. It will certainly help you get a handle on such questions.
_________________

Karishma
Veritas Prep | GMAT Instructor
My Blog

Save $100 on Veritas Prep GMAT Courses And Admissions Consulting
Enroll now. Pay later. Take advantage of Veritas Prep's flexible payment plan options.

Veritas Prep Reviews

CEO
CEO
User avatar
Joined: 09 Sep 2013
Posts: 2800
Followers: 206

Kudos [?]: 42 [0], given: 0

Premium Member
Re: A certain bakery ran a promotion code: a customer can buy x [#permalink] New post 25 Feb 2014, 09:55
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

Expert Post
Moderator
Moderator
User avatar
Joined: 20 Dec 2013
Posts: 155
GMAT 1: 720 Q49 V40
Followers: 1

Kudos [?]: 22 [0], given: 61

GMAT ToolKit User Premium Member Reviews Badge
Re: A certain bakery ran a promotion code: a customer can buy x [#permalink] New post 25 Feb 2014, 16:49
Expert's post
should have plugged in (as per the above advice)...

12[[(15/(X+3)]-[15/x]]=2
...
x^2+3x-270=0
...after doing a prime factorization of 270....
(x-15)(x+18)=0
x=15
_________________

MY GMAT BLOG - ADVICE - OPINIONS - ANALYSIS

Re: A certain bakery ran a promotion code: a customer can buy x   [#permalink] 25 Feb 2014, 16:49
    Similar topics Author Replies Last post
Similar
Topics:
1 Experts publish their posts in the topic gmat voucher or promotion code? bulbulkillsthegmat 21 31 Mar 2010, 04:30
4 Experts publish their posts in the topic GMAT payment voucher/promotion code benbo1234 20 19 Feb 2009, 19:49
3 Experts publish their posts in the topic For each customer, a bakery charges p dollars for the first dwag 8 19 Sep 2006, 15:19
2 Experts publish their posts in the topic Tom can buy a certain type-writer for Z1 dollars in city X, pb_india 3 02 May 2005, 11:49
Display posts from previous: Sort by

A certain bakery ran a promotion code: a customer can buy x

  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®.