It is currently 20 Nov 2017, 14:51

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 and y are integers and y = |x + 3| + |4 - x|, does y equals 7?

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

Hide Tags

Intern
Intern
avatar
Joined: 05 May 2013
Posts: 12

Kudos [?]: 2 [0], given: 6

GMAT ToolKit User
Re: If x and y are integers and y = |x + 3| + |4 - x|, does y equals 7? [#permalink]

Show Tags

New post 07 May 2013, 23:13
The answer is C as per above justification by manishuol.

I just wan to add, that care has to be taken not to break down the expression. For example, lx+3l is not equal to lxl + 3.

Kudos [?]: 2 [0], given: 6

Verbal Forum Moderator
User avatar
Joined: 10 Oct 2012
Posts: 627

Kudos [?]: 1387 [0], given: 136

Premium Member
Re: If x and y are integers and y = |x + 3| + |4 - x|, does y equals 7? [#permalink]

Show Tags

New post 08 May 2013, 01:48
mario1987 wrote:
Hi guys,
I would like to deeply understand how to deal with absolute value questions like the one attached.
Thank you very much


For the given question, note that you can get y=7 when both the values inside the mod, i.e. (x+3) & (4-x)>0 .It is so, because the variable(x) will get cancelled and you will get a constant value for y = 7, irrespective of the value of x.
Thus, x>-3 AND x<4.
_________________

All that is equal and not-Deep Dive In-equality

Hit and Trial for Integral Solutions

Kudos [?]: 1387 [0], given: 136

Senior Manager
Senior Manager
avatar
Joined: 21 Jan 2010
Posts: 329

Kudos [?]: 229 [0], given: 12

Re: If x and y are integers and y = |x + 3| + |4 - x|, does y equals 7? [#permalink]

Show Tags

New post 08 May 2013, 13:22
thirst4edu wrote:
If x and y are integers and y=|x+3| + |4-x|, does y equals 7?

(1) x < 4
(2) x > -3

Had a hard time solving this, would like to know how to solve this using number picking approach as well as algebraic approach. Thanks.

OA is
[Reveal] Spoiler:
C


At first i tried to apply the approach given in the gmatclub math guide regarding dealing with absolute value questions. But than i remembered that approach is for finding the solutions of an equation.
After further thought i looked at the question and than at
1) x < 4. Their can be infinite values of x less than 4. Some of which gives y= 4(3,2..etc) and some don't x = -10. INSUFFICIENT.
2)x > -3. Same as above. Some values give y=7(-2,-1..etc). Some don't x= 10. INSUFFICIENT.

Combining 1 and 2, we can see that all values -2,-1,0,1,2,3 given y=7. Hence SUFFICIENT.

Kudos [?]: 229 [0], given: 12

Intern
Intern
User avatar
B
Joined: 16 Jul 2011
Posts: 46

Kudos [?]: 3 [0], given: 165

Concentration: Marketing, Real Estate
GMAT 1: 550 Q37 V28
GMAT 2: 610 Q43 V31
Reviews Badge
Re: If x and y are integers and y = |x + 3| + |4 - x|, does y equals 7? [#permalink]

Show Tags

New post 30 Sep 2017, 11:35
Bunuel and other experts: Can't we solve absolute value questions by the simple strategy of plugging in numbers? That's how I solved this question. I understand that it takes slightly longer by plugging in numbers. But honestly, the properties of absolute values makes me go nuts. They are so confusing and it doesn't come to me naturally. Do you get absolute value questions a lot on the GMAT that I absolutely need to learn the properties or can I get away by solving these questions through the plug in numbers strategy?
_________________

"The fool didn't know it was impossible, so he did it."

Kudos [?]: 3 [0], given: 165

Intern
Intern
avatar
B
Joined: 06 Apr 2017
Posts: 8

Kudos [?]: 0 [0], given: 58

Location: India
Re: If x and y are integers and y = |x + 3| + |4 - x|, does y equal 7? [#permalink]

Show Tags

New post 02 Oct 2017, 08:03
zaarathelab wrote:
If x and y are integers and y = |x + 3| + |4 - x|, does y equal 7?

(1) x < 4
(2) x > -3


The equation can be divided for three ranges.
1. X<-3
2. Y>4
3. -3<=X<=4

If you solve for the third case, you will get Y=X+3+4-X=7 (Always True)
Rest two cases will provide you will equations, which might hold true.

Kudos [?]: 0 [0], given: 58

Intern
Intern
avatar
B
Joined: 24 Jan 2015
Posts: 13

Kudos [?]: [0], given: 18

Location: India
Re: If x and y are integers and y = |x + 3| + |4 - x|, does y equal 7? [#permalink]

Show Tags

New post 02 Oct 2017, 18:22
Hey nishitraj,

Little confused here could you explain by picking numbers for statement 1 and 2.

Kudos [?]: [0], given: 18

Expert Post
Math Expert
User avatar
P
Joined: 02 Aug 2009
Posts: 5213

Kudos [?]: 5855 [0], given: 117

Re: If x and y are integers and y = |x + 3| + |4 - x|, does y equal 7? [#permalink]

Show Tags

New post 02 Oct 2017, 20:03
Amerendra wrote:
Hey nishitraj,

Little confused here could you explain by picking numbers for statement 1 and 2.



Hi...

y=|x+3|+|4-x|

Without solving you can say for all values between -3 and 4, y will be 7 as any increase in x in one mod will be negated with decrease in other mod..

Let's see the statements
1) x<4...
Take x as 0..
y=|0+3|+|4-0|=3+4=7
Take x as -5
y=|-5+3|+|4-(-5)|=|-2|+|9|=2+9=11
So different answers
Insufficient
2) x>-3
Take x as -2
y=|-2+3|+|4-(-2)|=|1|+|4+2|=1+6=7
Take x as 7
y=|3+7|+|4-7|=10+3=13
Different answers
Insufficient

Combined sufficient

C
_________________

Absolute modulus :http://gmatclub.com/forum/absolute-modulus-a-better-understanding-210849.html#p1622372
Combination of similar and dissimilar things : http://gmatclub.com/forum/topic215915.html

Kudos [?]: 5855 [0], given: 117

Re: If x and y are integers and y = |x + 3| + |4 - x|, does y equal 7?   [#permalink] 02 Oct 2017, 20:03

Go to page   Previous    1   2   [ 27 posts ] 

Display posts from previous: Sort by

If x and y are integers and y = |x + 3| + |4 - x|, does y equals 7?

  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®.