|
|
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
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
13 May 2014, 06:31
Kudos
Bookmarks
D
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
75%
(hard)
Question Stats:
50% (01:50) correct
50%
(01:27)
wrong
based on 178
sessions
History
Date
Time
Result
Not Attempted Yet
Is x^2 greater than x - y?
(1) y - x is positive
(2) x > 1 and y > 1
I have a questions about that problem. The answer for (1) says that y - x is positive so x- y is negative ((which equals -1(y-x))
How can I get a general rule for the highlighted statement? Thanks for the answers.
(1) y - x is positive
(2) x > 1 and y > 1
I have a questions about that problem. The answer for (1) says that y - x is positive so x- y is negative ((which equals -1(y-x))
How can I get a general rule for the highlighted statement? Thanks for the answers.
Pure algebraic questions like this one are no longer part of the GMAT Data Sufficiency syllabus.
For relevant Data Sufficiency questions, please check the Data Sufficiency forum:
Data Sufficiency Forum
Data Sufficiency Forum
13 May 2014, 06:47
Kudos
Bookmarks
steilbergauf
Is x^2 greater than x-y?
Is \(x^2>x-y\)? (The question can be re-phrased as is \(x^2-x>-y\)?)
(1) y - x is positive --> \(y-x>0\) --> subtract y-x from both sides of the inequality:\(0>-(y-x)\) --> \(0>x-y\). Since \(x^2\geq{0}\) (the square of any number is more than or equal to 0), then \(x^2\geq{0}>x-y\). Sufficient.
(2) x>1 and y>1. Since \(x>1\), then \(x^2-x>0\) and since \(y\) is positive, then \(-y\) is negative. Thus, \((x^2-x=positive)>(-y=negative)\). Sufficient.
Answer: D.
As for your question: we can get \(0>x-y\) from \(y-x>0\) by subtracting y-x from both sides of that inequality.
Hope it's clear.
12 Jun 2015, 17:57
Kudos
Bookmarks
Hi steilbergauf,
Since your original post is over a year old, I'm not sure if you're still around, but here's some extra information about the question you asked...
In Fact 1, we're told that Y - X is POSITIVE.
This means that Y > X. As a simple example, let's choose Y = 5, X = 2...
Thus, Y - X = 5 - 2 = 3
If you "flip" the order of the variables, then the larger number (Y) is subtracted from the smaller number (X), so the result MUST be NEGATIVE.
3 - 5 = -2
This concept can be taken a step further in the following example. Assuming X and Y are real numbers AND X is NOT equal to Y, what is the value of the following fraction...?
(X-Y)/(Y-X) = ?
Here's a hint: TEST VALUES (pick a value for X and Y and plug them in). What do you end up with? If you change the numbers, what happens to the answer?
GMAT assassins aren't born, they're made,
Rich
Since your original post is over a year old, I'm not sure if you're still around, but here's some extra information about the question you asked...
In Fact 1, we're told that Y - X is POSITIVE.
This means that Y > X. As a simple example, let's choose Y = 5, X = 2...
Thus, Y - X = 5 - 2 = 3
If you "flip" the order of the variables, then the larger number (Y) is subtracted from the smaller number (X), so the result MUST be NEGATIVE.
3 - 5 = -2
This concept can be taken a step further in the following example. Assuming X and Y are real numbers AND X is NOT equal to Y, what is the value of the following fraction...?
(X-Y)/(Y-X) = ?
Here's a hint: TEST VALUES (pick a value for X and Y and plug them in). What do you end up with? If you change the numbers, what happens to the answer?
Since (X-Y) and (Y-X) are exact opposites of one another (meaning positive and negative versions of the same number), you'll ALWAYS end up with -1.
GMAT assassins aren't born, they're made,
Rich
