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

It is currently 30 Jul 2015, 17:13
GMAT Club Tests

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

Several: Percent Shortcut and Absolute value inequation

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Intern
Intern
avatar
Status: "
Joined: 22 Jan 2011
Posts: 42
Schools: IE- ESCP - Warwick
Followers: 0

Kudos [?]: 4 [0], given: 7

Several: Percent Shortcut and Absolute value inequation [#permalink] New post 27 Apr 2011, 07:50
00:00
A
B
C
D
E

Difficulty:

  25% (medium)

Question Stats:

87% (02:06) correct 13% (00:00) wrong based on 15 sessions
Hi all,


Just wondering what is your guys reasonning to QUICKLY solve a percentage such as 15% of 35, 50 $

I am refering as example as a question like 139, OG 12th Edition, Problem Solving:


A meal cost $ 35.50 adn there was no tax. If the tip was more than 10 pc but less than 15pc of the price, then the total amount paid should be:

A. 40-42
B. 39-41
C. 38-40
D. 37-39
E. 36-37

Fin here under my reasonning, I would appreciate your comments.

10 pc of 35.50= kidstuff! = 35, 50 + (35,50/10)= 39, 05

mmmm let's have a look at the answer choices, B seems to be correct at 80% sure (only answer including 30 as the least value), would be nice if I could confirm it by finding the other value.

15 pc of 35.50 believe it or not, it takes me about 1 min to find out that it is about 40,8... I would appreciate to know how you guys make such a percentage quickly?

Even by making 1,15* 35,50 it takes time to calculate it toroughly.

- Those is the 138 th question out of the 230 PS in the OG, what's the level of such and the questions before sub 600? At what question does it starts to be above 600 ? Not really fair from GMAC to provide just 1/4 or 1/3 of 600+ questions

- I am looking for a great ressource to review some theory about inequation and absolute value, free if possible..?
[Reveal] Spoiler: OA
Kaplan GMAT Prep Discount CodesKnewton GMAT Discount CodesManhattan GMAT Discount Codes
Expert Post
GMAT Tutor
avatar
Joined: 24 Jun 2008
Posts: 1174
Followers: 312

Kudos [?]: 979 [0], given: 4

Re: Several: Percent Shortcut and Absolute value inequation [#permalink] New post 27 Apr 2011, 10:35
Expert's post
To find 15% of a number:

- first find 10% of the number
- cut that in half; that will give you 5% of the number
- add the 10% and 5% figures to get 15% of the number

So if you want to find 15% of $8.80, you would:

- find 10%, which is 88 cents
- find 5% by cutting that in half, to get 44 cents
- add 88 and 44 cents to get $1.32

Similarly, to find 15% of $35.50,

- 10% of $35.50 is $3.55
- 5% of $35.50 is half of that, so is $1.775 --> since the question asks for an estimate only, you should round this off to $1.80 or $1.75 to make the final step simpler
- if we round off to $1.80, then 15% is very close to $3.55+$1.80 = $5.35
_________________

GMAT Tutor in Toronto

If you are looking for online GMAT math tutoring, or if you are interested in buying my advanced Quant books and problem sets, please contact me at ianstewartgmat at gmail.com

Director
Director
avatar
Joined: 01 Feb 2011
Posts: 760
Followers: 14

Kudos [?]: 74 [0], given: 42

Re: Several: Percent Shortcut and Absolute value inequation [#permalink] New post 27 Apr 2011, 15:27
10%(35.5) = 3.55
15%(35.5) = 5.325

total amount could have been 35.5+3.55 and 35.5+5.325

=> could have been between 39.05 and 40.625
=> approximately between 39 and 41

Answer is B.
Expert Post
Veritas Prep GMAT Instructor
User avatar
Joined: 16 Oct 2010
Posts: 5743
Location: Pune, India
Followers: 1444

Kudos [?]: 7584 [0], given: 186

Re: Several: Percent Shortcut and Absolute value inequation [#permalink] New post 27 Apr 2011, 17:36
Expert's post
Duke007 wrote:
Hi all,

- I am looking for a great ressource to review some theory about inequation and absolute value, free if possible..?


Check out our blog for some percentages, inequalities, modulus and other concepts:
http://www.veritasprep.com/blog/categor ... om/page/3/
_________________

Karishma
Veritas Prep | GMAT Instructor
My Blog

Get started with Veritas Prep GMAT On Demand for $199

Veritas Prep Reviews

Intern
Intern
avatar
Status: "
Joined: 22 Jan 2011
Posts: 42
Schools: IE- ESCP - Warwick
Followers: 0

Kudos [?]: 4 [0], given: 7

Re: Several: Percent Shortcut and Absolute value inequation [#permalink] New post 27 Apr 2011, 18:50
Thanks awfully :-)
SVP
SVP
avatar
Joined: 16 Nov 2010
Posts: 1678
Location: United States (IN)
Concentration: Strategy, Technology
Followers: 31

Kudos [?]: 364 [0], given: 36

Premium Member Reviews Badge
Re: Several: Percent Shortcut and Absolute value inequation [#permalink] New post 28 Apr 2011, 03:40
35.50 + 3.55 < x < 35.50 + 5.32

Answer - B
_________________

Formula of Life -> Achievement/Potential = k * Happiness (where k is a constant)

GMAT Club Premium Membership - big benefits and savings

Senior Manager
Senior Manager
User avatar
Joined: 08 Nov 2010
Posts: 419
WE 1: Business Development
Followers: 7

Kudos [?]: 57 [0], given: 161

GMAT ToolKit User
Re: Several: Percent Shortcut and Absolute value inequation [#permalink] New post 28 Apr 2011, 21:13
why do u even calculate the upper limit?
u have only one answer with 39! u r done!

and if u want to be sure sure - u can do quickly:
10% is 3.55 so 5% is half - around 1.7
so 3.5+1.5 = (a little more than) 5.

done!

no need to calculate it.
_________________

GMAT Club Premium Membership - big benefits and savings

Re: Several: Percent Shortcut and Absolute value inequation   [#permalink] 28 Apr 2011, 21:13
    Similar topics Author Replies Last post
Similar
Topics:
Experts publish their posts in the topic absolute value change sign on what side? agarwalmanoj2000 3 10 Jan 2012, 20:33
Experts publish their posts in the topic Absolute Value GMATD11 7 04 Apr 2011, 03:56
1 Absolute Value Region CMcAboy 4 21 Mar 2011, 18:16
30 Experts publish their posts in the topic For what range of values of x will the inequality fluke 21 16 Feb 2011, 23:20
Experts publish their posts in the topic absolute value modulus from math book ksharma12 4 22 Jun 2010, 14:33
Display posts from previous: Sort by

Several: Percent Shortcut and Absolute value inequation

  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®.