It is currently 21 Feb 2018, 19:08

Close

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

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Close

Request Expert Reply

Confirm Cancel

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

If x>y>0, is y<2?

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Expert Post
Math Revolution GMAT Instructor
User avatar
D
Joined: 16 Aug 2015
Posts: 4898
GPA: 3.82
If x>y>0, is y<2? [#permalink]

Show Tags

New post 16 Jan 2018, 01:28
00:00
A
B
C
D
E

Difficulty:

  85% (hard)

Question Stats:

52% (01:01) correct 48% (02:10) wrong based on 42 sessions

HideShow timer Statistics

[GMAT math practice question]

If \(x>y>0\), is \(y<2\)?

\(1) \frac{1}{x} = \frac{1}{2}\)
\(2) (\frac{1}{x})+(\frac{1}{y}) =1\)
[Reveal] Spoiler: OA

_________________

MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
Find a 10% off coupon code for GMAT Club members.
“Receive 5 Math Questions & Solutions Daily”
Unlimited Access to over 120 free video lessons - try it yourself
See our Youtube demo

1 KUDOS received
Intern
Intern
avatar
Joined: 11 Nov 2017
Posts: 10
Location: Germany
Schools: IESE '20 (II)
GMAT 1: 670 Q47 V34
GMAT 2: 700 Q49 V38
GPA: 2.5
Re: If x>y>0, is y<2? [#permalink]

Show Tags

New post 16 Jan 2018, 01:45
1
This post received
KUDOS
1) if 1/x = 1/2
then x=2
then 0<y<2 --> SUFF

since 1 is suff -> A or D

2)
-don't make the mistake to assume x and y are integers
if you do then the only solution for 1/x + 1/y = 1 would be for x=y=2 <-- this goes against the given information.

-we know both x and y are positive(>0) so 1/x and 1/y will also be positive
-this means that neither will be bigger than 1 otherwise 2) has no solution
--> suff
(example solution is: x=4, y=4/3 --> 1/4 + 1/(4/3) = 1 --> 1/4 + 3/4 = 1)

--> D: each statement alone is suff
Expert Post
Math Revolution GMAT Instructor
User avatar
D
Joined: 16 Aug 2015
Posts: 4898
GPA: 3.82
Re: If x>y>0, is y<2? [#permalink]

Show Tags

New post 18 Jan 2018, 00:39
=>

Forget conventional ways of solving math questions. For DS problems, the VA (Variable Approach) method is the quickest and easiest way to find the answer without actually solving the problem. Remember that equal numbers of variables and independent equations ensure a solution.

Since we have 2 variables (\(x\) and \(y\)) and 1 equation ( \(x > y\)), D is most likely to be the answer.

Condition 1)
\(\frac{1}{x} = \frac{1}{2}\) implies that \(x = 2\). Since \(x > y\), we must have \(y < 2.\)
Condition 1) is sufficient.

Condition 2)
The original condition \(x > y > 0\) implies that \(\frac{1}{x} < \frac{1}{y}\).
Using \(\frac{1}{x} + \frac{1}{y} = 1\) and \(\frac{1}{x} < \frac{1}{y}\) together, we can see that \(\frac{1}{y} > \frac{1}{2}\).
Thus, \(0 < y < 2\).
Condition 2) is sufficient.

Therefore, the answer is D.
Note: The VA approach tells us that the answer is most likely to be D, since this is a CMT(Common Mistake Type) 4B question.
Condition 1) is easy to check, but condition 2) is more difficult to work with. If you can’t figure out condition 2), you should choose D as the answer.
Answer: D
_________________

MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
Find a 10% off coupon code for GMAT Club members.
“Receive 5 Math Questions & Solutions Daily”
Unlimited Access to over 120 free video lessons - try it yourself
See our Youtube demo

Re: If x>y>0, is y<2?   [#permalink] 18 Jan 2018, 00:39
Display posts from previous: Sort by

If x>y>0, is y<2?

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.