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

 It is currently 26 May 2019, 17:16

### 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

# M31-35

Author Message
TAGS:

### Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 55277

### Show Tags

14 Jun 2015, 14:54
00:00

Difficulty:

35% (medium)

Question Stats:

72% (01:31) correct 28% (01:43) wrong based on 43 sessions

### HideShow timer Statistics

In which quadrant of the coordinate plane does the point $$(x,y)$$ lie?

(1) $$xy = 7$$

(2) $$5x + 7y < -\frac{1}{2}$$

_________________
Math Expert
Joined: 02 Sep 2009
Posts: 55277

### Show Tags

14 Jun 2015, 14:54
1
Official Solution:

In which quadrant of the coordinate plane does the point $$(x,y)$$ lie?

(1) $$xy = 7$$. This implies that $$x$$ and $$y$$ are either both negative or both positive, thus $$(x,y)$$ lies either in III quadrant or in I quadrant. Not sufficient.

(2) $$5x + 7y < -\frac{1}{2}$$. Both $$x$$ and $$y$$ can be negative or one of them can be negative and another positive. Not sufficient.

Notice that from this statement it's NOT possible both $$x$$ and $$y$$ to be positive: $$5x + 7y = positive + positive = positive$$, not negative number $$-\frac{1}{2}$$.

(1)+(2) Since (2) rules out possibility of both $$x$$ and $$y$$ being positive, then from (1) we are left with negative $$x$$ and $$y$$: $$(x,y)$$ lies either in III quadrant. Sufficient.

_________________
Intern
Joined: 08 Nov 2012
Posts: 4
Location: United States
WE: Engineering (Other)

### Show Tags

24 Jul 2015, 23:19
1
I think this is a high-quality question and I agree with explanation. The link to the discussion in the website is broken.

Thanks
Aurion
Math Expert
Joined: 02 Sep 2009
Posts: 55277

### Show Tags

25 Jul 2015, 02:11
Aurion wrote:
I think this is a high-quality question and I agree with explanation. The link to the discussion in the website is broken.

Thanks
Aurion

Thank you for reporting. We are looking into it.
_________________
Manager
Joined: 10 Sep 2014
Posts: 80
GPA: 3.5
WE: Project Management (Manufacturing)

### Show Tags

30 Mar 2018, 20:53
Bunuel I'm not sure that how "x and y are either both negative or both positive, lies either in III quadrant or in I quadrant., " and Both xx and yy can be negative or one of them can be negative and another positive." Please provide detailed solution.
Math Expert
Joined: 02 Sep 2009
Posts: 55277

### Show Tags

31 Mar 2018, 01:19
1
Bunuel I'm not sure that how "x and y are either both negative or both positive, lies either in III quadrant or in I quadrant., " and Both xx and yy can be negative or one of them can be negative and another positive." Please provide detailed solution.

1. Check this: https://gmatclub.com/forum/math-coordin ... 87652.html

The first quadrant consists of all points with positive x and y coordinates. The product of x and y coordinates = positive.
The third quadrant consists of all points with negative x and y coordinates. The product of x and y coordinates = positive.

2. $$5x + 7y < -\frac{1}{2}$$.

Here if both x and y are positive, 5x + 7y, would have been positive, NOT negative, so both x and y cannot be negative. Which means that either both of them are negative or one of them is negative and another positive.
_________________
Director
Joined: 20 Sep 2016
Posts: 637
Location: India
Concentration: Strategy, Operations
GPA: 3.95
WE: Operations (Real Estate)

### Show Tags

24 Aug 2018, 07:05
02 min 11 sec
than the general system result
of 11 min 14 sec

Could you please explain the later statement. " You time result is better
than the general system result
of 11 min 14 sec" what does it mean? general systemresult? chetan2u @sayantc2k Bunuel
Math Expert
Joined: 02 Sep 2009
Posts: 55277

### Show Tags

24 Aug 2018, 07:09
02 min 11 sec
than the general system result
of 11 min 14 sec

Could you please explain the later statement. " You time result is better
than the general system result
of 11 min 14 sec" what does it mean? general systemresult? chetan2u @sayantc2k Bunuel

Could you please post the screenshot? Thank you.
_________________
Director
Joined: 20 Sep 2016
Posts: 637
Location: India
Concentration: Strategy, Operations
GPA: 3.95
WE: Operations (Real Estate)

### Show Tags

24 Aug 2018, 07:58
Bunuel wrote:
02 min 11 sec
than the general system result
of 11 min 14 sec

Could you please explain the later statement. " You time result is better
than the general system result
of 11 min 14 sec" what does it mean? general systemresult? chetan2u @sayantc2k Bunuel

Could you please post the screenshot? Thank you.

i found this analysis in "question stats" next to "show explanation"Could you please also explain " the average time incorrect and average tme correct " because on forum the average time is different. Also the above mentioned doubt regarding the general system result . Bunuel
>> !!!

You do not have the required permissions to view the files attached to this post.

Manager
Joined: 22 Jun 2017
Posts: 178
Location: Argentina
Schools: HBS, Stanford, Wharton
GMAT 1: 630 Q43 V34

### Show Tags

25 Feb 2019, 13:35
I think this is a high-quality question and I agree with explanation.
_________________
The HARDER you work, the LUCKIER you get.
Re M31-35   [#permalink] 25 Feb 2019, 13:35
Display posts from previous: Sort by

# M31-35

Moderators: chetan2u, Bunuel

 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®.