GMAT Question of the Day - Daily to your Mailbox; hard ones only

 It is currently 19 Jan 2019, 11:22

### 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

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

## Events & Promotions

###### Events & Promotions in January
PrevNext
SuMoTuWeThFrSa
303112345
6789101112
13141516171819
20212223242526
272829303112
Open Detailed Calendar
• ### FREE Quant Workshop by e-GMAT!

January 20, 2019

January 20, 2019

07:00 AM PST

07:00 AM PST

Get personalized insights on how to achieve your Target Quant Score.
• ### Free GMAT Strategy Webinar

January 19, 2019

January 19, 2019

07:00 AM PST

09:00 AM PST

Aiming to score 760+? Attend this FREE session to learn how to Define your GMAT Strategy, Create your Study Plan and Master the Core Skills to excel on the GMAT.

# If x > 2 and y > -1, then which of the following

Author Message
TAGS:

### Hide Tags

Retired Moderator
Joined: 25 Feb 2013
Posts: 1220
Location: India
GPA: 3.82
If x > 2 and y > -1, then which of the following  [#permalink]

### Show Tags

09 Sep 2017, 00:30
1
1
00:00

Difficulty:

55% (hard)

Question Stats:

64% (02:08) correct 36% (01:28) wrong based on 109 sessions

### HideShow timer Statistics

If $$x>2$$ and $$y>-1$$, then which of the following statements must be true?

A. $$xy>-2$$
B. $$-x<2y$$
C. $$xy<-2$$
D. $$-x>2y$$
E. $$x<-2y$$
Intern
Joined: 19 Sep 2016
Posts: 15
Re: If x > 2 and y > -1, then which of the following  [#permalink]

### Show Tags

09 Sep 2017, 02:41
Nice question .But can you please explain difference between 1st and 2nd choice
VP
Status: Learning
Joined: 20 Dec 2015
Posts: 1041
Location: India
Concentration: Operations, Marketing
GMAT 1: 670 Q48 V36
GRE 1: Q157 V157
GPA: 3.4
WE: Engineering (Manufacturing)
Re: If x > 2 and y > -1, then which of the following  [#permalink]

### Show Tags

09 Sep 2017, 03:07
A xy>−2
x=8 y =0.9
xy =-7.2 so xy<-2 therefore not true

B −x<2y
Notice that the LHS will be always negative as x will always be positive
x=2.1 y=-0.9
-2.1<-1.8 true this will hold true for any valye of Y if it holds for -0.9 as it is the quite close to -1 .
True

C xy<−2

x=2.1 y=-0.9
xy =-1.89
but -1.89 > -2 so not true

D −x>2y

x=2.1 y=6
-2.1< 12 so not true

E x<−2y
Clearly not true
x=2.1 y=0.9
2.1>-1.8
so not true .
_________________

Retired Moderator
Joined: 25 Feb 2013
Posts: 1220
Location: India
GPA: 3.82
Re: If x > 2 and y > -1, then which of the following  [#permalink]

### Show Tags

09 Sep 2017, 08:02
surbhipuri wrote:
Nice question .But can you please explain difference between 1st and 2nd choice

Hi surbhipuri
Mathematically you cannot multiply two inequalities until you know the signs of both the variables. In this inequality we know that $$x$$ is positive but $$y$$ can be positive, negative or $$0$$ (since $$y>-1$$ this implies that $$y$$ can be $$-0.5, 0,$$ or $$1$$ etc.)
if $$y$$ is negative then on multiplying it with $$x$$, the sign of the inequality will change but if $$y$$ is positive then there will be no change in the inequality sign.
so if you are multiplying $$x$$ and $$y$$ directly then Option A cannot be the answer
Retired Moderator
Joined: 25 Feb 2013
Posts: 1220
Location: India
GPA: 3.82
If x > 2 and y > -1, then which of the following  [#permalink]

### Show Tags

10 Sep 2017, 05:57
1
3
niks18 wrote:
If $$x>2$$ and $$y>-1$$, then which of the following statements must be true?

A. $$xy>-2$$
B. $$-x<2y$$
C. $$xy<-2$$
D. $$-x>2y$$
E. $$x<-2y$$

OE

$$x>2$$ this implies $$-x<-2$$ ----------------$$(1)$$
$$y>-1$$, multiplying both side of the inequality by $$2$$, we get $$2y>-2$$ ---------------$$(2)$$
Combining equations $$(1)$$ & $$(2)$$, it is clear that
$$-x<2y$$
Hence Option B

---------------------------------
Another method could be to test some values of $$x$$ & $$y$$ as per the given condition but that might take more than a minute to arrive at the final answer
Senior Manager
Joined: 02 Apr 2014
Posts: 474
GMAT 1: 700 Q50 V34
Re: If x > 2 and y > -1, then which of the following  [#permalink]

### Show Tags

27 Jan 2018, 04:06
x > 2, y > -1
adding two inequalities x + y > 2 - 1 => x + y > 1

(B). -x < 2y
0 < x + 2y
=> 0 < x + y + y
=> 0 < (>1) + y (from above, x+y > 1)
=> 0 < (>1) + (>-1) (from above, y > -1)
=> which will always true => say y = -0.9, then (>1) + (-0.9) will be greater than zero
Re: If x > 2 and y > -1, then which of the following &nbs [#permalink] 27 Jan 2018, 04:06
Display posts from previous: Sort by

# If x > 2 and y > -1, then which of the following

 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®.