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

It is currently 20 Sep 2014, 04:19

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

Data Sufficiency Strategy Guide

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

Kudos [?]: 65 [11] , given: 23

Data Sufficiency Strategy Guide [#permalink] New post 05 Apr 2012, 07:25
11
This post received
KUDOS
15
This post was
BOOKMARKED
I've been working with the Advanced Quant guide by ManhattanGMAT for some time now and really benefited a lot from their excellent strategy guide on DS questions. I decided to summarize the basic steps of their DS section with an emphasis on what I think to be the most important points and combined this with my own experiences. I thought this might be beneficial to other users as well. I do not intend to violate any copyrights, I will merely focus on the basic principles without using any of the examples. The Advanced Quant Strategy guide is excellent and I think you take the most from it by really going through all the "Try-It" examples and all the questions in the back of the book. The book has a lot more to offer than the DS section and the other sections will definitely make you a smarter and better test taker, so buy the book if you find this helpful.

DS Strategy:


  • Make sure to write out all the important information in the question stem, whether it be certain (integer, pos/neg etc.) constraints, equations or the actual question. I noticed that this definitely helps you to prevent a lot of silly mistakes, such as forgetting about a constraint that is crucial to answering the question, but it also takes a lot of time. In my opinion it's best to try to pick up the constraints and then keep them in the back of your mind. When you analyze each statement, quickly get back to the question stem and look for the constraints, you save a couple of seconds this way and avoid silly mistakes due to forgetting about important information as good as possible.
  • Always rephrase any equations, inequalities, fractions etc. Most of the simplifications that the GMAT uses are of the same pattern. For example try to write expressions with exponents in such a way that all of the bases are the same, or whenever you see a sum with root contained in it, try to multiply by its conjugate. The more problems you do the more you become accustomed to the GMAT style of simplifying expressions.
  • Separate the statements on your paper cleary. I think this is really important, because statement carryover is a lot more likely, if you don't do it. Also you should always actively think about the danger of statement carryover, that way you are less likely to do it.
  • Be a contrarian. You always have to look at all the possible scenarios when analyzing the statements, one trick that sometimes help you to detect that a statement is insufficient is to look at the other statement and deliberately try to violate that statement. I found this tip to be really helpful, because a lot of the times the opposite of the other statement is exactly the scenario that proves insufficiency.
  • Assume nothing. On most questions where there aren't any constraints given, people sometimes still assume that there is e.g an integer constraint and thus only test integer cases. By really paying attention to what is given and whats NOT given, you can find the correct answer on a lot of questions.
  • Compute the completion. When people see quadratic expressions, they sometimes assume that there are two solutions and that this proves insufficiency, since you can't find a single solution. This is a big mistake, on some occasions the value you are looking for is a product of two variables and plugging the two solutions in the product you actually get the same result. I found myself commiting this mistake quite often. You should always finish your calculation, unless you're 100% sure that you're correct. You don't want to spend a lot of time on a question, only to find yourself getting the question wrong, because you skipped the last calculation step, which would have cost you maybe 10 seconds.
  • Beware of inequalities. Inequalities are really important in DS questions. You should especially look out for inequalities that combine with integer constraints, this will often give you the solution. If you forget about the constraint, the inequality in the statement might be of little use. Also look out for variables in the denominator in an inequality, never multiply the inequality by a variable, unless you know the sign of the variable. The GMAT uses this rule a lot in inequality DS questions.
  • Use a scenario chart. In some problems there are only a handful of different options, this is especially true in positive/negative and even/odd type of questions. Create a table with each variable and each statement in it's own column and different scenarios in each row. Then pick numbers that satsify the given statements and see if there's only one solution to the question or multiple solutions. As soon as you find two possible solutions the statement is insufficient and you can go on to the next statement. If both statements are insufficient, use only those values for the variables that satsify both statements.
  • Test numbers systematically. I think this is the most important skill in DS questions. Obviously you need to know all the basics to perform well on this test and it's always good to be able to prove sufficiency or insufficiency elagantly in an algebraic way. But sometimes a statement is just too difficult to handle algebraically or it takes too much time to solve algebraically. No matter how difficult a statement is, you can always pick numbers to prove sufficiency or insufficiency. But don't just test numbers randomly, you should have a systematic approach to it. MGMAT suggests to always have a standard set of numbers, which can be adjusted to the constraints given in the question and statement. The numbers are -2,-3/2,-1,-1/2,0,1/2,1,3/2 and 2. On some occasions it's also crucial to pick boundary values, e.g if a question ask whether x is less than or equal to 1 and a statement gives you x² less than or equal to 1.3, you can e.g pick x=1.1 to prove insufficiency.

Those are in my opinion the most important stategic points to remember for all DS questions. There a couple of more points in the guide, but I didn't think they were that helpful.

Last edited by bb on 12 Apr 2012, 06:47, edited 1 time in total.
Formatting
Manhattan GMAT Discount CodesKaplan GMAT Prep Discount CodesKnewton GMAT Discount Codes
Manager
Manager
avatar
Joined: 06 Jul 2011
Posts: 214
Location: Accra, Ghana
Followers: 1

Kudos [?]: 24 [0], given: 39

GMAT Tests User
Re: Data Sufficiency Strategy Guide [#permalink] New post 07 Apr 2012, 23:30
My good friend, thanks for this strategy guide for Data Sufficiency. I have been looking for one since I started my GMAT Prep. Data Sufficiency is a real challenge for me, but I am very determined to crack it.
Intern
Intern
avatar
Joined: 11 Apr 2012
Posts: 42
Followers: 0

Kudos [?]: 4 [0], given: 93

Re: Data Sufficiency Strategy Guide [#permalink] New post 12 Apr 2012, 22:09
Thank You very mu ch.That was very helpful.
Intern
Intern
User avatar
Joined: 27 Sep 2011
Posts: 7
Location: United States
Concentration: General Management, International Business
GPA: 3.6
WE: Accounting (Energy and Utilities)
Followers: 0

Kudos [?]: 5 [0], given: 2

Re: Data Sufficiency Strategy Guide [#permalink] New post 17 Oct 2012, 17:43
thanks a bunch for the guide.
I have the same problem - i have noticed that my weakness is on DS problems.
I'm using MGMAT and I'm on my 3rd book. Every book there's at least 2 practice tests with DS and I always get them wrong.
I get frustrated but I try harder each time. :)
Manager
Manager
User avatar
Joined: 04 Jul 2013
Posts: 85
Location: Australia
Concentration: Strategy, Technology
Schools: HEC Jan'16 (M)
GMAT 1: 690 Q47 V38
GPA: 3.2
WE: Information Technology (Consulting)
Followers: 3

Kudos [?]: 15 [0], given: 29

Reviews Badge
Re: Data Sufficiency Strategy Guide [#permalink] New post 25 Jul 2013, 05:20
Thanks. DS is proving to be a real problem area for me. Will definitely try to incorporate the above points.
_________________

Take care to get what you like or you will be forced to like what you get!!

Expert Post
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 23482
Followers: 3504

Kudos [?]: 26494 [0], given: 2712

Re: Data Sufficiency Strategy Guide [#permalink] New post 25 Jul 2013, 05:55
Expert's post
ashkul123 wrote:
Thanks. DS is proving to be a real problem area for me. Will definitely try to incorporate the above points.


Other posts on DS strategies:
trouble-with-quant-some-tips-traps-that-might-help-you-34329.html
tips-on-approaching-ds-questions-104945.html
http://gmatclub.com/blog/2010/01/verita ... questions/
http://gmatclub.com/blog/2010/09/elimin ... fficiency/
http://gmatclub.com/blog/2011/08/gmat-d ... tion-type/
http://gmatclub.com/blog/2011/08/must-k ... trategies/
http://gmatclub.com/blog/2011/08/kaplan ... questions/
data-sufficiency-strategy-guide-130264.html

Hope it helps.
_________________

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

SVP
SVP
User avatar
Joined: 09 Sep 2013
Posts: 2432
Followers: 197

Kudos [?]: 38 [0], given: 0

Premium Member
Re: Data Sufficiency Strategy Guide [#permalink] New post 19 Aug 2014, 16:58
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

Re: Data Sufficiency Strategy Guide   [#permalink] 19 Aug 2014, 16:58
    Similar topics Author Replies Last post
Similar
Topics:
Experts publish their posts in the topic Best Strategy for Data Sufficiency for a newbie. sejpara 1 06 Sep 2014, 00:11
3 Experts publish their posts in the topic Strategy for Data Sufficiency ZF 10 30 May 2014, 04:18
what is best guide for data Sufficiency kormbo2002 1 19 Oct 2010, 06:25
1 Data Sufficiency Strategy terp26 1 11 Jan 2008, 07:11
Data Sufficiency rbcola 2 14 Aug 2006, 11:50
Display posts from previous: Sort by

Data Sufficiency Strategy Guide

  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®.