I am pathetic at Quant i need a strategy time no issue.

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Hi guys,
I am really poor in maths and have been since my school days, im looking to turn a corner since i really want to do well in my GMAT im not worried about Verbal since i can score in the low 30's quite easily. I have absolutely no clue when it comes to D.S. and am looking at material to help me understand the concept better..
I would really appreciate it if some one helped me with a strategy and recommended some material with which i can improve my quant skills. Time is not an issue for me so i can work on ironing my flaws..

All help is greatly appreciated...

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by JasLamba » Wed Dec 09, 2009 5:24 pm

As per DS:

There are sub questions in the DS format. You need to be able to prove whether the information is given is suffice to answer the question. A simple example:

If x+5 = 10, what is the value of x?

1. x = 3
2. y = 3

In essence, you can notice that the first statement gives us enough info to tackle the question. Then, when looking at the second statement independently you will notice that the variable y has no relevance in the equation and it is NOT enough information to solve the actual question.

In order to do well on DS there are a few things you should know about.
1. Know what they are asking. In the example above it is quite obvious what they are asking for. But in more complex problems you will see information presented in an unfamiliar way to you, so you will have to manipulate the equation to get to the core. Check this example out:
If x+y = 15, what is the value of xy?

1. 3(x+y)= 45
2. y = 10

Basically, you are asked to solve for X times Y but in order to solve this you will need both of the values. In statement one, you are essentially given the same equation as the statement just a bit more layered out. 3x + 3y = 45 is essentially the same system of equations as the question. So, you are not able to discern the values of x nor y. X could be 7 and y could be 8. Or x could be 10 and y 5. Thus, xy in the first scenario would yield 56, whilst in the second scenario yield 50. So, statement 1 may look a bit daunting at first but really there is alot of fluff - you can simplify it. Statement 2 on the other hand gives us the value of y. This enables us to find the value of X which would be 5 and thus, 10*5 = 50. A single value can be yielded thanks to this statement. So it would be our answer (B).

Well these examples are quite basic but keep in mind the following:
- practice DS as you need to memorize the answer choices - eventually you want to be good at these as they save lots of time in the Quant section.
- know the question types. The two examples above were value question (value questions ask for 1 solution) to better illustrate my point take a look at this:

x^y= 81, what is the value of x?

1. x is positive
2. y = 4

statement 1 tells us that x is positive so what? x could be 3^4 =81 or 9^2 =81.
statement 2 tells us that y = 4. We know that 3^4 = 81 so x may be either +3 or -3. Hopefully this helps in illustrating my value point (we have 2 values for x, not one). Thus, the data is insufficient in this case as well.
If we combine both statements we will have sufficiency as you will see that x=3. (one value, so data is sufficient.

- other question types include yes/no questions. I suggest you look at Eric Bahns blog - I find his DS experience much more enlightening that my basic examples.
- Unfortunately for DS , there is no material other than GMAT material as it is a very GMAT specific question type. So master your basics and then practice practice practice will get you at a good level.
- in DS it is essential to manipulate equations particularly in the question stem. Use all the info provided as it all will help you. There are also particular strategies for tackling DS with Elimination... if you want I can explain them in another post.

As per materials:
- if you go through the forum - make some strategic searches such as quant lists, formulas, anytype of keywords that come to your head - all of this will help you in finding some decent material.
- what I did was go through a learning express math basics called 1001 problems. Essentially, this book is broken down into a couple of chapters with problem sets - arithmetic, decimals, fractions, percentages, geometry, and ratios. These are all concepts tested so use this. Princeton PR Math Review is good (essentially the same as 1001 problems but less practice and some more theory). If you do another book of this sort perhaps 501 word problems by learning express you can exercise your math muscles and practice word problems which are CRUCIAL for the GMAT. All these sources have no direct relationship with GMAT but more than anything used for strengthening your fundamentals. It is a good starting point if your not upto par.
- Following this you can use any of the books recommended by the pros here in the forum - kaplan, princeton review, nova. Maybe those three are enough to give you some understanding of GMAT material.
- Following this, I would take it to the next level and do some MGMAT - MGMAT guides tailor your studies and specialize it - because they are experts they know what to teach you for you to be succesful and by now you should know alot more about the GMAT. This will hone your skills further and take it to the next level.
- Now, you should be ready for some official guide problems. OG 11, OG 12, and Math supplements. If you can do these... practice, review, re-do, review, re-do... identify weak spots, re-learn, practice... you should be fine. These are official test problems so it doesnt get any more realistic than this.

Since you have time, you can do anything to improve your odds in becoming a successful GMATician.
Hope I didn't get too boring...I have a tendency not to reread what I write before posting so if you have any questions let me know.