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

It is currently 14 Dec 2018, 13:45

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 in December
PrevNext
SuMoTuWeThFrSa
2526272829301
2345678
9101112131415
16171819202122
23242526272829
303112345
Open Detailed Calendar
  • Typical Day of a UCLA MBA Student - Recording of Webinar with UCLA Adcom and Student

     December 14, 2018

     December 14, 2018

     10:00 PM PST

     11:00 PM PST

    Carolyn and Brett - nicely explained what is the typical day of a UCLA student. I am posting below recording of the webinar for those who could't attend this session.
  • Free GMAT Strategy Webinar

     December 15, 2018

     December 15, 2018

     07:00 AM PST

     09:00 AM PST

    Aiming to score 760+? Attend this FREE session to learn how to Define your GMAT Strategy, Create your Study Plan and Master the Core Skills to excel on the GMAT.

If a large pizza has a radius that is 30% larger that that of a medium

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

Hide Tags

Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 51215
If a large pizza has a radius that is 30% larger that that of a medium  [#permalink]

Show Tags

New post 17 Aug 2018, 11:20
00:00
A
B
C
D
E

Difficulty:

  15% (low)

Question Stats:

81% (00:48) correct 19% (01:18) wrong based on 57 sessions

HideShow timer Statistics

If a large pizza has a radius that is 30% larger that that of a medium pizza, what is the percent increase in area between a medium and a large pizza?

A. 30
B. 36
C. 60
D. 69
E. 90

_________________

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

Director
Director
User avatar
P
Status: Learning stage
Joined: 01 Oct 2017
Posts: 931
WE: Supply Chain Management (Energy and Utilities)
Premium Member
Re: If a large pizza has a radius that is 30% larger that that of a medium  [#permalink]

Show Tags

New post 17 Aug 2018, 11:31
1
Bunuel wrote:
If a large pizza has a radius that is 30% larger that that of a medium pizza, what is the percent increase in area between a medium and a large pizza?

A. 30
B. 36
C. 60
D. 69
E. 90


If radius of medium pizza is 'r', then radius of larger pizza is 1.3r.
So, \(A_{L}=\pi*(1.3r)^2\) & \(A_{M}=\pi*r^2\)

%increase in area=\(\frac{\pi*(1.3r)^2-\pi*r^2}{\pi*r^2}\)*100=(1.69-1)*100=69%

Ans. (D)
_________________

Regards,

PKN

Rise above the storm, you will find the sunshine

Senior SC Moderator
avatar
V
Joined: 22 May 2016
Posts: 2207
Premium Member CAT Tests
If a large pizza has a radius that is 30% larger that that of a medium  [#permalink]

Show Tags

New post 18 Aug 2018, 08:11
Bunuel wrote:
If a large pizza has a radius that is 30% larger that that of a medium pizza, what is the percent increase in area between a medium and a large pizza?

A. 30
B. 36
C. 60
D. 69
E. 90

I. Assign values

Radius and area
Let radius of medium pizza, \(r=10\)
AREA of medium pizza: \(a=πr^2=100π\)

Radius of large pizza, \(R=(10*1.3)=13\)
OR
\(R=(r+.30r)=1.3r=(1.3*10)=13\)
AREA of large pizza, \(A=(π* 13^2)=169π\)

[Percent increase, mental math: 169 is 69% greater than 100 - Answer D]

Percent increase in area = percent change

Percent change: \(\frac{Change}{Original}*100\)

Change: \((169π-100π)=69π\)
Original (area of medium pizza) = \(100π\)

Percent increase in area:
\((\frac{69π}{100π})*100=(.69*100)=69\) %

Answer D

II. Shortcut formula for overall percent change

We have successive percent changes because the radius increases by 30% TWICE
(\(r*r*π\)) => \((R*R*π)\)

SHORTCUT formula
Overall percent change for two successive percent changes:
\(A+B+\frac{A*B}{100}\) percent

\(A\) = first percent change
\(B\) = second percent change

\(30+30+\frac{30*30}{100}\)

\((60+\frac{900}{100})=(60+9)=69\) percent increase

Answer D
Intern
Intern
avatar
B
Joined: 06 Mar 2018
Posts: 1
Re: If a large pizza has a radius that is 30% larger that that of a medium  [#permalink]

Show Tags

New post 18 Aug 2018, 09:53
Bunuel wrote:
If a large pizza has a radius that is 30% larger that that of a medium pizza, what is the percent increase in area between a medium and a large pizza?

A. 30
B. 36
C. 60
D. 69
E. 90




Large Area = (169/100) Medium Area
%Increase = 69
Board of Directors
User avatar
P
Status: QA & VA Forum Moderator
Joined: 11 Jun 2011
Posts: 4277
Location: India
GPA: 3.5
WE: Business Development (Commercial Banking)
GMAT ToolKit User Premium Member CAT Tests
Re: If a large pizza has a radius that is 30% larger that that of a medium  [#permalink]

Show Tags

New post 18 Aug 2018, 10:18
Bunuel wrote:
If a large pizza has a radius that is 30% larger that that of a medium pizza, what is the percent increase in area between a medium and a large pizza?

A. 30
B. 36
C. 60
D. 69
E. 90


\(30 + 30 + \frac{30*30}{100}\)

= 69, Answer must be (D) 69
_________________

Thanks and Regards

Abhishek....

PLEASE FOLLOW THE RULES FOR POSTING IN QA AND VA FORUM AND USE SEARCH FUNCTION BEFORE POSTING NEW QUESTIONS

How to use Search Function in GMAT Club | Rules for Posting in QA forum | Writing Mathematical Formulas |Rules for Posting in VA forum | Request Expert's Reply ( VA Forum Only )

Target Test Prep Representative
User avatar
G
Status: Head GMAT Instructor
Affiliations: Target Test Prep
Joined: 04 Mar 2011
Posts: 2830
Re: If a large pizza has a radius that is 30% larger that that of a medium  [#permalink]

Show Tags

New post 20 Aug 2018, 10:08
Bunuel wrote:
If a large pizza has a radius that is 30% larger that that of a medium pizza, what is the percent increase in area between a medium and a large pizza?

A. 30
B. 36
C. 60
D. 69
E. 90


We can let the medium pizza = 10 and the large = 13; thus:

Area of medium = 100π

Area of large = 169π

Using the percent change formula: (New - Old)/Old x 100 we obtain:

(169π - 100π)/100π x 100 = 69/100 = 69%

Answer: D
_________________

Jeffery Miller
Head of GMAT Instruction

GMAT Quant Self-Study Course
500+ lessons 3000+ practice problems 800+ HD solutions

GMAT Club Bot
Re: If a large pizza has a radius that is 30% larger that that of a medium &nbs [#permalink] 20 Aug 2018, 10:08
Display posts from previous: Sort by

If a large pizza has a radius that is 30% larger that that of a medium

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


Copyright

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®.