It is currently 21 Nov 2017, 11:03

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 is a positive number less than 10, is z greater than

  post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
Manager
Manager
User avatar
Joined: 17 Dec 2008
Posts: 171

Kudos [?]: 173 [0], given: 0

If x is a positive number less than 10, is z greater than [#permalink]

Show Tags

New post 17 Feb 2009, 09:06
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

100% (00:10) correct 0% (00:00) wrong based on 0 sessions

HideShow timer Statistics

This topic is locked. If you want to discuss this question please re-post it in the respective forum.

If x is a positive number less than 10, is z greater than the average of x and 10?

(1) On the number line, z is closer to 10 than it is to x.
(2) z = 5x

Kudos [?]: 173 [0], given: 0

SVP
SVP
User avatar
Joined: 07 Nov 2007
Posts: 1790

Kudos [?]: 1089 [0], given: 5

Location: New York
Re: DS - Number line [#permalink]

Show Tags

New post 17 Feb 2009, 10:14
ConkergMat wrote:
If x is a positive number less than 10, is z greater than the average of x and 10?

(1) On the number line, z is closer to 10 than it is to x.
(2) z = 5x




(1) Sufficient.
average.. = mid point of x and 10
if it is closer to 10.. z> average

(z)
avg = x+10/2

z= 5x

x=0.1 z=0.5 avg = 5.x
z<avg

when x = 5 z = 25 avg= 7.5
z> avg

not sufficient

A
_________________

Your attitude determines your altitude
Smiling wins more friends than frowning

Kudos [?]: 1089 [0], given: 5

Manager
Manager
avatar
Joined: 11 Sep 2008
Posts: 57

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

Re: DS - Number line [#permalink]

Show Tags

New post 17 Feb 2009, 10:20
Agree w/ A

Here it is visually:

Number line:
1)===X===Z=10===


Visually, the Average: (X+10)/2 is clearly less than Z.

2) just pick numbers.

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

Manager
Manager
User avatar
Joined: 10 Jan 2009
Posts: 108

Kudos [?]: 205 [0], given: 0

Re: DS - Number line [#permalink]

Show Tags

New post 17 Feb 2009, 10:30
-------------------------------------
1) As z is closer to 10 than it is to x, we can have z > 10 or z < 10 on the condition that it stays closer to 10 than to x.

Case 1.

If z > 10, then the value of z will always be greater than average of x & 10.
For ex. z = 12 & x = 7 ---> Will satisfy option 1.

Now avg.(x+10) = 17/2 = 8.5, which is less than 12

Case 2.

Now let us see if z < 10.

If we consider z=9 & x=7, then avg.(x+10) = 17/2 = 8.5, which is less than 9. You can check by taking any legal values.


Another way of solving option 1:

We know that z > 10 will always satisfy, so we will consider only for z < 10.

As 10-z < z-x,
Therefore, 2z -x > 10
or, z > (x+10)/2

So, option 1 is sufficient.

-------------------------------------

2) z = 5x

So possible values for x = 1,2,...9

For x=1, z=5 So, avg(x+10) = 11/2 = 5.5, which is greater than z

For x=2, z=10 So, avg(x+10) = 12/2 = 6, which is less than z

So, option 2 is not sufficient.
-------------------------------------

So, only option 1 is sufficient to answer the question.

HTH
_________________

+++ Believe me, it doesn't take much of an effort to underline SC questions. Just try it out. +++
+++ Please tell me why other options are wrong. +++

~~~ The only way to get smarter is to play a smarter opponent. ~~~

Kudos [?]: 205 [0], given: 0

Director
Director
User avatar
Joined: 01 Apr 2008
Posts: 872

Kudos [?]: 861 [0], given: 18

Name: Ronak Amin
Schools: IIM Lucknow (IPMX) - Class of 2014
Re: DS - Number line [#permalink]

Show Tags

New post 22 Feb 2009, 04:56
x2suresh wrote:
ConkergMat wrote:
If x is a positive number less than 10, is z greater than the average of x and 10?

(1) On the number line, z is closer to 10 than it is to x.
(2) z = 5x




(1) Sufficient.
average.. = mid point of x and 10
if it is closer to 10.. z> average

(z)
avg = x+10/2

z= 5x

x=0.1 z=0.5 avg = 5.x
z<avg

when x = 5 z = 25 avg= 7.5
z> avg

not sufficient

A

Hi x2suresh,
A says: Z is closer to 10 than Z is closer to X.
x can be 2, Z can be 3.

Average of x and 10 is 6 , Z < x.

x can be 2, Z can be 8.
Average of x and 10 is 6, Z > x.

What you say is correct if Z>5!! Please explain.

Kudos [?]: 861 [0], given: 18

Senior Manager
Senior Manager
avatar
Joined: 08 Jan 2009
Posts: 325

Kudos [?]: 180 [0], given: 5

Re: DS - Number line [#permalink]

Show Tags

New post 22 Feb 2009, 05:28
Economist wrote:
x2suresh wrote:
ConkergMat wrote:
If x is a positive number less than 10, is z greater than the average of x and 10?

(1) On the number line, z is closer to 10 than it is to x.
(2) z = 5x




(1) Sufficient.
average.. = mid point of x and 10
if it is closer to 10.. z> average

(z)
avg = x+10/2

z= 5x

x=0.1 z=0.5 avg = 5.x
z<avg

when x = 5 z = 25 avg= 7.5
z> avg

not sufficient

A

Hi x2suresh,
A says: Z is closer to 10 than Z is closer to X.
x can be 2, Z can be 3.

Average of x and 10 is 6 , Z < x.

x can be 2, Z can be 8.
Average of x and 10 is 6, Z > x.

What you say is correct if Z>5!! Please explain.


hi

A : Z is closer to 10 than to X.

By taking X =2 and Z=3 you have actually made Z closer to 10 when compared with X from 10.But the question says the distance b/w Z and 10 < distance b/w Z and X.

hope you got it.

Kudos [?]: 180 [0], given: 5

Manager
Manager
User avatar
Joined: 19 Aug 2006
Posts: 238

Kudos [?]: 14 [0], given: 0

Re: DS - Number line [#permalink]

Show Tags

New post 22 Feb 2009, 21:41
Yup, only A.

B does not apply, because we can easily find a case when z<(x+10)/2 and also when z>(x+10)/2:

1. if x=1 => z=5x => so z=5
(1+10)/2 = 5.5 => 5<5.5

2. if x=3 => z=5x => so z=15
(3+10)/2 = 6.5 => 15>6.5

Kudos [?]: 14 [0], given: 0

Manager
Manager
avatar
Joined: 04 Sep 2006
Posts: 113

Kudos [?]: 63 [0], given: 0

Re: DS - Number line [#permalink]

Show Tags

New post 23 Feb 2009, 08:01
WHEN Z IS CLOSER TO 10 , WHAT ARE THE UPPER AND LOWER VALUES FOR Z

WILL THE VALUES OF Z BE 9.5 TO 10.5 OR 9 TO 11

Kudos [?]: 63 [0], given: 0

Manager
Manager
avatar
Joined: 11 Sep 2008
Posts: 57

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

Re: DS - Number line [#permalink]

Show Tags

New post 23 Feb 2009, 08:28
vcbabu wrote:
WHEN Z IS CLOSER TO 10 , WHAT ARE THE UPPER AND LOWER VALUES FOR Z

WILL THE VALUES OF Z BE 9.5 TO 10.5 OR 9 TO 11


There is no limit. maybe x = 9.9, and z = 9.9999 or z = 150

The main point is that 1) tells you that z is closer to 10 than Z is to X, it shows you that (minimum): AVG(X,10)<Z

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

Re: DS - Number line   [#permalink] 23 Feb 2009, 08:28
Display posts from previous: Sort by

If x is a positive number less than 10, is z greater than

  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®.