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

It is currently 26 May 2015, 04:20

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

Tips and Hints for Specific Quant Topics (with Examples)

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Expert Post
13 KUDOS received
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 27494
Followers: 4315

Kudos [?]: 42346 [13] , given: 6012

Tips and Hints for Specific Quant Topics (with Examples) [#permalink] New post 03 Jun 2014, 05:01
13
This post received
KUDOS
Expert's post
183
This post was
BOOKMARKED

New project from GMAT Club


Tips and Hints for Specific Quant topics with Examples.
We will be posting 2 questions every week to illustrate common shortcuts and tips for solving quant questions faster and better - Join in and bookmark this topic or subscribe to it to get notifications when new topics and tips get posted.


Number Properties:
PS question
DS Question
Tips and hints

Divisibility/Multiples/Factors:
PS question
DS question
Tips and hints

Remainders:
PS question
DS question
Tips and hints

Inequalities:
PS question
DS question
Tips and hints

Absolute Values:
PS question
DS question
Tips and hints

Algebra:
PS question
DS question
Tips and hints

Exponents and roots:
PS question
DS question
Tips and hints

Combinations:
PS question
DS question

Every week we'll be publishing 2 brand new (PS an DS) questions from each and every topic tested on the GMAT along with respective tips and hints.
Get Kudos points for correct solutions.
Share your tips and hints below and get Kudos points


[Reveal] Spoiler:
Attachment:
hints-tricks-shortcuts.jpg
hints-tricks-shortcuts.jpg [ 4.87 KiB | Viewed 16832 times ]

_________________

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

GMAT Club Premium Membership - big benefits and savings


Last edited by Bunuel on 26 Jul 2014, 15:13, edited 37 times in total.
Updated Links
Kaplan GMAT Prep Discount CodesKnewton GMAT Discount CodesVeritas Prep GMAT Discount Codes
Expert Post
3 KUDOS received
MBA Section Director
User avatar
Affiliations: GMAT Club
Joined: 21 Feb 2012
Posts: 1512
Location: India
City: Pune
GPA: 3.4
WE: Business Development (Manufacturing)
Followers: 204

Kudos [?]: 1401 [3] , given: 1169

GMAT ToolKit User Premium Member CAT Tests
Re: Tips and Hints for Specific Quant Topics (with Examples) [#permalink] New post 26 Jul 2014, 10:23
3
This post received
KUDOS
Expert's post
1
This post was
BOOKMARKED
Here is a Tip on work/rate problems. I would like to introduce Percent approach to solve Work/rate problems.

Let's consider basic example.
A can complete a certain task in 10 hours and B can complete the same task 20 hours.
We assume that the task is 100%
So if A can complete the task in 10 hours, we can say he is taking 10 hours to complete 100% of task. That means in one hour he is finishing \(\frac{100%}{10}\) or 10% task.
Similarly B is completing \(\frac{100%}{20}\) or 5% task in one hour.
If they start working together(at their respective rates), they would finish (10% + 5%) or 15% task in one hour.
So to finish entire task together, it would take them \(\frac{100}{15}\) or \(6\frac{2}{3}\) hours.



Now lets apply this logic on following GMAT Type question. This is question is taken from Bunuel's Set of Mixed questions.

Three workers, A, B, and C, can complete a certain task in 10, 5 and x hours respectively. A starts working alone and 2 hours later B joins. After another 2 hours joins C. After that A, B, and C together complete the task in 15 minutes. What is the value of x?

A. 1
B. 1.25
C. 2
D. 2.5
E. 4

Three workers, A, B, and C, can complete a certain task in 10, 5 and x hours respectively
So in one hour A is completing 10% task, B is completing 20% task, and C is completing \((\frac{100}{x})%\) task.


A starts working alone and 2 hours later B joins.
Before B joins, A will have worked for 2 hours and have finished 20% task. That means when B joins A, total remaining work will be 80%


After another 2 hours joins C.
Using Similar logic, At the time of C's joining, A & B will have finished 60% task. Remaining work will be 20%


After that A, B, and C together complete the task in 15 minutes.
So A, B, C together complete remaining 20% task in 15 mins or in \(\frac{15}{60} hours\)

So we have that \(\frac{20%}{(10% + 20% + 100/x)} = \frac{15}{60}\)

Solving for X, we get 750x = 1500 ----------> x = 2

Hope that helps!!
_________________

Be the coolest guy in the MBA Forum - Be a threadmaster!

Have a blog? Feature it on GMAT Club!

All MBA Resources All 'Sticky' Topics at one place

Please share your profiles for this application season: 2015 Profiles w/ Admit/Dings Results!

GMAT Club Premium Membership - big benefits and savings

Next Generation GMATClub CATS with Brilliant Analytics.


Expert Post
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 27494
Followers: 4315

Kudos [?]: 42346 [0], given: 6012

Re: Tips and Hints for Specific Quant Topics (with Examples) [#permalink] New post 26 Jul 2014, 15:13
Expert's post
Re: Tips and Hints for Specific Quant Topics (with Examples)   [#permalink] 26 Jul 2014, 15:13
    Similar topics Author Replies Last post
Similar
Topics:
Regarding specific Quant Topics - alphonsa 0 17 Sep 2014, 06:49
15 Absolute Value: Tips and hints Bunuel 2 09 Jul 2014, 06:04
13 Inequalities: Tips and hints Bunuel 0 02 Jul 2014, 03:33
6 Remainders: Tips and hints Bunuel 0 23 Jun 2014, 02:33
40 Number Properties: Tips and hints Bunuel 7 04 Jun 2014, 11:25
Display posts from previous: Sort by

Tips and Hints for Specific Quant Topics (with Examples)

  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®.