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

It is currently 23 Oct 2014, 05:38

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 supermarket sells a cerain brand of jelly in two jars of d

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Director
Director
avatar
Joined: 29 Nov 2012
Posts: 929
Followers: 12

Kudos [?]: 312 [0], given: 543

A supermarket sells a cerain brand of jelly in two jars of d [#permalink] New post 18 Jan 2013, 03:49
3
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  25% (medium)

Question Stats:

81% (01:51) correct 19% (01:09) wrong based on 63 sessions
Attachment:
Cylinder.jpg
Cylinder.jpg [ 13.67 KiB | Viewed 1808 times ]
A supermarket sells a certain brand of jelly in two jars of different sizes, as shown above. Jar A is a right circular cylinder with inside diameter D and inside Height h; Jar B is a right circular cylinder with inside diameter T and inside height 2h. Assuming each jar is filled to capacity, which jar of jelly will cost less per unit volume?

(1) The relationship between the diameters of Jar A and Jar B is 3T = 2D.
(2) Jar A costs $1.59 and Jar B costs 1.39


I'm interested in a detailed solution if this question was asked as a problem solving question. Any help will be appreciated. Thanks!
[Reveal] Spoiler: OA

_________________

Click +1 Kudos if my post helped...

Amazing Free video explanation for all Quant questions from OG 13 and much more http://www.gmatquantum.com/og13th/

GMAT Prep software What if scenarios gmat-prep-software-analysis-and-what-if-scenarios-146146.html


Last edited by Bunuel on 18 Jan 2013, 03:52, edited 1 time in total.
Edited the question.
Expert Post
1 KUDOS received
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 23393
Followers: 3609

Kudos [?]: 28828 [1] , given: 2852

Re: A supermarket sells a cerain brand of jelly in two jars of d [#permalink] New post 18 Jan 2013, 04:05
1
This post received
KUDOS
Expert's post
Image
A supermarket sells a certain brand of jelly in two jars of different sizes, as shown above. Jar A is a right circular cylinder with inside diameter D and inside Height h; Jar B is a right circular cylinder with inside diameter T and inside height 2h. Assuming each jar is filled to capacity, which jar of jelly will cost less per unit volume?

(1) The relationship between the diameters of Jar A and Jar B is 3T = 2D.
(2) Jar A costs $1.59 and Jar B costs 1.39

The volume of a cylinder is given by: volume_{cylinder}=\pi*{r^2}*h.

From (1) we have that t/2=d/3, thus volume_A=\pi*{(\frac{d}{2})^2}*h and volume_B=\pi*{(\frac{t}{2})^2}*2h=\pi*{(\frac{d}{3})^2}*2h.

From (2) we have that 1 unit volume of A costs \frac{1.59}{\pi*{(\frac{d}{2})^2}*h}=\frac{4*1.59}{\pi{d^2}h} and 1 unit volume of B costs \frac{1.39}{\pi*{(\frac{d}{3})^2}*2h}=\frac{4.5*1.39}{\pi{d^2}h}. Now, all we need to do is to see which one is less 4*1.59 or 4.5*1.39.

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

Manager
Manager
avatar
Joined: 21 Jul 2012
Posts: 61
Followers: 0

Kudos [?]: 6 [0], given: 32

Re: A supermarket sells a cerain brand of jelly in two jars of d [#permalink] New post 24 Mar 2013, 09:24
Bunuel wrote:
Image
A supermarket sells a certain brand of jelly in two jars of different sizes, as shown above. Jar A is a right circular cylinder with inside diameter D and inside Height h; Jar B is a right circular cylinder with inside diameter T and inside height 2h. Assuming each jar is filled to capacity, which jar of jelly will cost less per unit volume?

(1) The relationship between the diameters of Jar A and Jar B is 3T = 2D.
(2) Jar A costs $1.59 and Jar B costs 1.39

The volume of a cylinder is given by: volume_{cylinder}=\pi*{r^2}*h.

From (1) we have that t/2=d/3, thus volume_A=\pi*{(\frac{d}{2})^2}*h and volume_B=\pi*{(\frac{t}{2})^2}*2h=\pi*{(\frac{d}{3})^2}*2h.

From (2) we have that 1 unit volume of A costs \frac{1.59}{\pi*{(\frac{d}{2})^2}*h}=\frac{4*1.59}{\pi{d^2}h} and 1 unit volume of B costs \frac{1.39}{\pi*{(\frac{d}{3})^2}*2h}=\frac{4.5*1.39}{\pi{d^2}h}. Now, all we need to do is to see which one is less 4*1.59 or 4.5*1.39.

Hope it's clear.


Bunuel - Actually my confusion arises with the answer explanation on prep, it says 1.39 / (pi*(2/9D)^2*h) = 6.255 / (pi*D^2*h). I know this is simple algebra but can you walk me through how I could easily convert this in 2 min if I were not able to see that t/2=d/3 and I kept it in the form T=2/3D. Thanks so much for your help with these problems.
Re: A supermarket sells a cerain brand of jelly in two jars of d   [#permalink] 24 Mar 2013, 09:24
    Similar topics Author Replies Last post
Similar
Topics:
2 Experts publish their posts in the topic A grocery store sells two varieties of jelly bean jars, and LGOdream 7 06 Aug 2011, 03:44
12 Experts publish their posts in the topic A feed store sells two varieties of birdseed: Brand A, which umaa 9 17 Dec 2009, 14:48
1 A supermarket sells both a leading brand of laundry powder a andrehaui 16 28 May 2007, 05:27
CR - Best-selling computer brands rookie06 12 01 Oct 2006, 13:12
A salesman sells two equally priced brands of ice cream, for gayathri 2 30 Nov 2004, 09:55
Display posts from previous: Sort by

A supermarket sells a cerain brand of jelly in two jars of d

  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®.