Data Suffiency Question

Question

Hello, 
I had a quick question regarding data suffiency question:

So lets if statment 1 is sufficient would you take that into consideration when looking into statment 2 then? Or do you still evaluate it separately?

So for the question I posted statment 1 is suffiencent but I was wondering if I take that into as an assumption when looking at statement 2?

cat2010 · Answer

No while dealing with statement 2 go without consideration initially .

Flow for DS should be like following.

1.Statement 1 sufficient /insufficient alone.
2.Statement 2 sufficient /insufficient alone.

If only Statement 1 sufficient Mark A as answer.
If only Statement 2 sufficient Mark B as answer.
If Both Statements are sufficient Mark D as answer.

Now If Both Statements are insufficient alone ,consider them together

If together statement are sufficient but not alone ,mark C as answer .
If together statement are insufficient also alone insufficient, mark E as answer .

egmat · Answer

Hi  shamyt10 ,

Thanks for your query.

GENERAL PRINCIPLES - Solving DS questions:    
  Solving any DS question must always begin with a complete analysis of its question stem. The information in the stem is to be used with both statements - individually or together. 
 Once you finish stem analysis and come to the statements, you MUST evaluate each statement  individually  without dragging any  knowledge/information  from the other statement. 
 Here is the correct process after stem analysis: 
  Analyze statement 1 completely. If it is sufficient, reject choices B, C, and E; if it is insufficient, reject choices A and D.  
 Next, when you analyze statement 2, completely  forget  about statement 1. This is irrespective of whether statement 1 comes out sufficient.  
 If each statement is insufficient alone, you combine both statements. This is the  ONLY  time that the information from one statement is used with that from the other.

EXAMPLE:    
Let us look at a simple example to understand what happens when one drags information from one statement into the other.

Question:   If x and y are the length and the breadth of a rectangle, respectively, find the area of the rectangle. 
  1. x = 36/y
2. y = 4

Solution:

Statement 1:    
From  statement 1 alone , at a first glance, it may appear that since we have two variables and one equation, we cannot find unique values of x and y. 
But do we even need the values of x and y to evaluate statement 1? No! 
  x = 36/y implies xy = 36, which precisely is the area of the rectangle.

Since we get a SURE yes (or a UNIQUE answer) to the question asked, statement 1 is  SUFFICIENT.  (Note that I took this example since it had statement 1 sufficient just as you did in your question.)

Statement 2:    
Now, let’s move to  statement 2:  (We will see this both ways – with and without dragging statement 1 into 2)

Without dragging statement 1 (CORRECT approach):   
  Statement 2 alone gives us that y = 4. 
  Since nothing has been said about x, we cannot find the area, i.e., xy.   
 Hence, statement 2 alone is  insufficient .   
 
  Dragging statement 1 (INCORRECT approach):   
  From statement 1, we got x = 36/y. 
  If we drag this into statement 2, which gives y = 4, we will incorrectly infer that x = 36/y = 9.     
This will make us feel that we can find the area (= xy) from statement 2 also. So, we would incorrectly conclude that statement 2 is  SUFFICIENT  as well, when we were actually supposed to evaluate statement 2 in isolation.

Hope this helps!

Best, 
Aditi Gupta 
Quant Expert, e-GMAT

Archit3110 · Answer

use below for DS
AD/BCE

if #1 is insufficient eliminate option A& D
later check #2 
if sufficient alone then option B 
if both #1 & #2 together are sufficient then option C
if both #1 & #2 together are not sufficient then option E

shamyt10 · Answer

Thank you everyone for your help! Really cleared it all up for me!

Data Suffiency Question

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