Forum Home > GMAT > Quantitative > Problem Solving (PS)
Events & Promotions
|
|
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.
Dec 1310:00 AM EST
-12:00 PM EST
Have you ever wondered how to score a PERFECT 805 on the GMAT? Meet Julia, a banking professional who used the Target Test Prep course to achieve this incredible feat. Julia's story is nothing short of an inspiration.
Dec 1410:00 AM EST
-12:00 PM EST
Think a 100% GMAT Verbal score is out of your reach? Target Test Prep will make you think again! Our course uses techniques such as topical study and spaced repetition to maximize knowledge retention and make studying simple and fun.
Dec 1411:00 AM IST
-01:00 PM IST
Attend this session to learn how to Deconstruct arguments, Pre-Think Author’s Assumptions, and apply Negation Test.- Dec 15
11:00 AM IST
-01:00 PM IST
Attend this free GMAT Algebra Webinar and learn how to master the most challenging Inequalities and Absolute Value problems with ease. 
Dec 1608:00 AM PST
-11:59 PM PST
GMAT Club 12 Days of Christmas is a 4th Annual GMAT Club Winter Competition based on solving questions. This is the Winter GMAT competition on GMAT Club with an amazing opportunity to win over $40,000 worth of prizes!
13 Apr 2016, 05:27
Kudos
Bookmarks
A
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
5%
(low)
Question Stats:
88% (01:30) correct
12%
(02:01)
wrong
based on 151
sessions
History
Date
Time
Result
Not Attempted Yet
If x and y are integers and √x−√y equals an odd integer, which of the following must be an even integer?
I. xy
II. x^2 + y^2
III. x/y
A. I only
B. I and II
C. II only
D. I, II, and III
E. None of these
I. xy
II. x^2 + y^2
III. x/y
A. I only
B. I and II
C. II only
D. I, II, and III
E. None of these
13 Apr 2016, 06:25
Kudos
Bookmarks
sqrt(x) - sqrt(y) = odd
sqrt(x) + sqrt(y) must also be = odd
(sqrt(x) - sqrt(y))*(sqrt(x) + sqrt(y)) = odd * odd
x - y = odd
even - odd = odd
odd - even = odd
I) xy = even? Yes. Since one term is even
II) x^2 + y^2 = even?
x^2 + y^2 - 2xy = odd
x^2 + y^2 = odd + even = odd
So x^2 + y^2 is not even
III) x/y = even?
If x = 6 and y = 3 then yes
If x = 3 and y = 2 then no
So x/y is not always even.
Answer: A
sqrt(x) + sqrt(y) must also be = odd
(sqrt(x) - sqrt(y))*(sqrt(x) + sqrt(y)) = odd * odd
x - y = odd
even - odd = odd
odd - even = odd
I) xy = even? Yes. Since one term is even
II) x^2 + y^2 = even?
x^2 + y^2 - 2xy = odd
x^2 + y^2 = odd + even = odd
So x^2 + y^2 is not even
III) x/y = even?
If x = 6 and y = 3 then yes
If x = 3 and y = 2 then no
So x/y is not always even.
Answer: A
14 Apr 2016, 00:01
Kudos
Bookmarks
If x and y are integers and √x−√y equals an odd integer, which of the following must be an even integer?
I. xy
II. x^2 + y^2
III. x/y
A. I only
B. I and II
C. II only
D. I, II, and III
E. None of these
Given that √x−√y = odd Int.
This means that one of the 2 should be odd and the other even. (Even/odd - Odd/Even = Odd). Implies x or y is even and the other is odd.
With this in mind:
I must be true - odd x even always even. (eliminate C and E).
II Not true. E + O is always odd. (Eliminate D and B).
Need not test the III.
Answer A.
I. xy
II. x^2 + y^2
III. x/y
A. I only
B. I and II
C. II only
D. I, II, and III
E. None of these
Given that √x−√y = odd Int.
This means that one of the 2 should be odd and the other even. (Even/odd - Odd/Even = Odd). Implies x or y is even and the other is odd.
With this in mind:
I must be true - odd x even always even. (eliminate C and E).
II Not true. E + O is always odd. (Eliminate D and B).
Need not test the III.
Answer A.
