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

 It is currently 21 Aug 2018, 18:58

### 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

# If equation |x| + |y| = 5 encloses a certain region on the

Author Message
Manager
Joined: 15 Nov 2007
Posts: 133
If equation |x| + |y| = 5 encloses a certain region on the  [#permalink]

### Show Tags

18 Jan 2008, 00:38
1
If equation |x| + |y| = 5 encloses a certain region on the graph, what is the area of that region?

* 5
* 10
* 25
* 50
* 100

i don't even know how to evaluate a statement like that...

--== Message from GMAT Club Team ==--

This is not a quality discussion. It has been retired.

If you would like to discuss this question please re-post it in the respective forum. Thank you!

To review the GMAT Club's Forums Posting Guidelines, please follow these links: Quantitative | Verbal Please note - we may remove posts that do not follow our posting guidelines. Thank you.
CEO
Joined: 17 Nov 2007
Posts: 3484
Concentration: Entrepreneurship, Other
Schools: Chicago (Booth) - Class of 2011
GMAT 1: 750 Q50 V40

### Show Tags

18 Jan 2008, 00:46
1
D

Just draw it.
we have a square with diagonal=5*2=10

$$Area=a^2=\frac{(\sqrt2*a)^2}{2}=\frac{(diagonal)^2}{2}=\frac{(10)^2}{2}=50$$
Attachments

t58639.gif [ 10.49 KiB | Viewed 1127 times ]

_________________

HOT! GMAT TOOLKIT 2 (iOS) / GMAT TOOLKIT (Android) - The OFFICIAL GMAT CLUB PREP APP, a must-have app especially if you aim at 700+ | PrepGame

Manager
Joined: 15 Nov 2007
Posts: 133

### Show Tags

18 Jan 2008, 01:06
walker wrote:
D

Just draw it.
we have a square with diagonal=5*2=10

$$Area=a^2=\frac{(\sqrt2*a)^2}{2}=\frac{(diagonal)^2}{2}=\frac{(10)^2}{2}=50$$

sweet... kudos +1... check back on the exponent question i had for me.
Director
Joined: 01 Jan 2008
Posts: 601

### Show Tags

18 Jan 2008, 07:55
my approach was similar to walker's - it's important to draw it to visualize, then obviously the area of each triangle is 5*5/2 = 25/2 and there are 4 triangles. the answer is 50.
SVP
Joined: 04 May 2006
Posts: 1773
Schools: CBS, Kellogg

### Show Tags

19 Jan 2008, 02:41
walker wrote:
D

Just draw it.
we have a square with diagonal=5*2=10

$$Area=a^2=\frac{(\sqrt2*a)^2}{2}=\frac{(diagonal)^2}{2}=\frac{(10)^2}{2}=50$$

At first, I dont know how to solve this problem, but when I see your drawing, I read it as:

Keep x=0, you had y = + - 5, and vice versa, keep y=0, you had x = +-5.

Do you have any tips for absolute value problem? When problem involves x and y, I am in block.
_________________
CEO
Joined: 17 Nov 2007
Posts: 3484
Concentration: Entrepreneurship, Other
Schools: Chicago (Booth) - Class of 2011
GMAT 1: 750 Q50 V40

### Show Tags

19 Jan 2008, 03:05
sondenso wrote:
Do you have any tips for absolute value problem? When problem involves x and y, I am in block.

The right but long approach is:

$$|x| + |y| = 5$$

is equal:

$$x+y=5\text{ if x\ge0;y\ge0}$$
$$x-y=5\text{ if x\ge0;y<0}$$
$$-x+y=5\text{ if x<0;y\ge0}$$
$$-x-y=5\text{ if x<0;y<0}$$

shortcut:

your drawing have to be symmetric for x and y. Therefore you can draw only x+y=5 (I quadrant) and use mirror symmetry
_________________

HOT! GMAT TOOLKIT 2 (iOS) / GMAT TOOLKIT (Android) - The OFFICIAL GMAT CLUB PREP APP, a must-have app especially if you aim at 700+ | PrepGame

Manager
Joined: 11 Jan 2008
Posts: 54

### Show Tags

07 Feb 2008, 01:19
can we take 3,2 or 4,1 as points?
Since the absolute value will always be "5".

-Jack
CEO
Joined: 17 Nov 2007
Posts: 3484
Concentration: Entrepreneurship, Other
Schools: Chicago (Booth) - Class of 2011
GMAT 1: 750 Q50 V40

### Show Tags

07 Feb 2008, 01:54
jackychamp wrote:
can we take 3,2 or 4,1 as points?
Since the absolute value will always be "5".

-Jack

we can but these points are not vertexs of the square and therefore, the points cannot help us to find area.
_________________

HOT! GMAT TOOLKIT 2 (iOS) / GMAT TOOLKIT (Android) - The OFFICIAL GMAT CLUB PREP APP, a must-have app especially if you aim at 700+ | PrepGame

Non-Human User
Joined: 09 Sep 2013
Posts: 7780
Re: If equation |x| + |y| = 5 encloses a certain region on the  [#permalink]

### Show Tags

17 Feb 2017, 17:34
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.

--== Message from GMAT Club Team ==--

This is not a quality discussion. It has been retired.

If you would like to discuss this question please re-post it in the respective forum. Thank you!

To review the GMAT Club's Forums Posting Guidelines, please follow these links: Quantitative | Verbal Please note - we may remove posts that do not follow our posting guidelines. Thank you.

_________________
Re: If equation |x| + |y| = 5 encloses a certain region on the &nbs [#permalink] 17 Feb 2017, 17:34
Display posts from previous: Sort by

# If equation |x| + |y| = 5 encloses a certain region on the

Moderator: chetan2u

# Events & Promotions

 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®.