I seem to have issues with Data Sufficiency. Generally, it

Question

I seem to have issues with Data Sufficiency. Generally, it seems to be about any type of math problem presented in this way. If I get a geometry problem in the PS format, I have no trouble with it, but in the DS, i'll take forever to get the answer.

Can anyone provide some tips with regard to how to answer DS questions?

On a specific level, I think inequalities give me the most trouble in DS and PS. Any help with inequalities would be great. Either a link to more questions or just anythign would be great.

stingraybullray · Answer

In case of number property problems: pay close attention to the questions stem and statements. look closely for +ve, -ve, integer.

Some times, if statement 1 is sufficient and statement 2 is insufficient, combining statement 2 with 1 will be sufficient too. This is a trap. In this case the answer is always A but not C.

rishi2377 · Answer

Morris, I assume that you know the basic rules regarding inequalities.
as far as number properties are concern, test every equation with +ve,-ve, fractions, 0 and one.
For other type of questions, look for the short cuts. 90% of the gmat question have an easy way hidden behind complex equation.
DS is quite intimidating but it is the biggest time saver as well, since more often than not, it doesn't need big calculations but quick and sharp thinking.....there is always a pattern in GMAt question and dont worry with appropriate practice you will start recognising the pattern and this will help.

As far as inequalities are concern, treat the inequality sign as (=) just remember the rules regarding when and how you have to change the sign.

thx and best of luck
Rishi

jallenmorris · Answer

I am very familiar with the rules of inequalities such as when to change the sign.

-2x > y
x < y/-2

or x/-2 > y = x < -2y

Change the sign when multiply/dividing by a negative number.

My problem is when they say something like "When x^4 + y^4 = z^4, is x^2 + y^2 > z^2." Then give some additional data. It's hard for me to plug all necessary numbers to get a feel on how to answer that question by plugging in numbers.

I think a scientific way to pick numbers would help...like always do these numbers in this order "-1, 1, 0, 1/2 (if not specifcally an integer), 2,etc..)"

Can you all tell me how you approach DS generally speaking?

durgesh79 · Answer

For any DS question follow the "AD" - "BCE" rule religiously ... hope you know the method..

For inequalities DS questions, some times it helps to change the statement or question stem in two parts... I'll give an example..
suppose statement 1 : x/(a+b) > 1
we know that multiplying with a -ve number will reverse the sign of the inequality.
We can divide the statement 1 in two parts
1A. when (a+b) is +ve; x > (a+b)
1B. when (a+b) is -ve; x < (a+b)
for statement 1 to be sufficient, it has to sufficient for both 1A and 1B.

also making a number line on scratch paper helps... like for this example

-----------------------|---------|---------|------------------------
....value if x in 1B-->(a+b) 0 (a+b)<--value of x in 1A....

Simply the question stem. Example. Is 4x^2 - 12x + 9 = 0,
actually its asking 'Is (2x-3)^2 = 0' or 'Is x = 3/2'

For Geomatry DS, I draw a diagram on scratch paper. diagrams on question (sometimes) are deceptive

If traditional methods fail. Try plugging example values.... with an attitude of trying to prove that the statement is not suff ... i.e. try to prove option E...... think of example values which satisfy both statement 1 and 2 but are far apart so that the answer of the question is different.....

durgesh79 · Answer

Not necessarily integers, This wasn’t from any question. I was trying to explain how I use number line to determine sufficiency and pick values… guess it dint come out very clear..

I seem to have issues with Data Sufficiency. Generally, it

Prep Toolkit

Top 5 GMAT Debrief Videos

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards