Find all School-related info fast with the new School-Specific MBA Forum

It is currently 30 Jul 2016, 01:16
GMAT Club Tests

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.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

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

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

Hide Tags

1 KUDOS received
Manager
Manager
avatar
Joined: 30 Aug 2005
Posts: 186
Followers: 1

Kudos [?]: 13 [1] , given: 0

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

Show Tags

New post 08 Nov 2005, 04:40
1
This post received
KUDOS
9
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  95% (hard)

Question Stats:

43% (03:05) correct 57% (02:24) wrong based on 385 sessions

HideShow timer Statistics

This one is from GMATPREP as well.
DS:

If x<10 and n is a positive integer, is z>(x+10)/2? (average of x and 10)

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

I am getting (D) as answer because (1) seems to be good enough info to conclude that z>(x+10)/2. Ofcourse, it is clear that (2) is ok too. But the answer is B.

Thanks!

MODERATOR: EDITED THE QUESTION.

ORIGINAL QUESTION:


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

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

(2) z = 5x
[Reveal] Spoiler: OA

Last edited by Bunuel on 15 Oct 2013, 14:07, edited 3 times in total.
EDITED THE QUESTION.
SVP
SVP
User avatar
Joined: 28 May 2005
Posts: 1723
Location: Dhaka
Followers: 7

Kudos [?]: 224 [0], given: 0

 [#permalink]

Show Tags

New post 08 Nov 2005, 05:48
I think it is C.

let's look at I) z is closer to 10 than x. and x is less than 10.

lest pick number if x= 1 and z=9 then (x+10)/2 = 5.5 which is less than z
how ever if x=1 and z=2 then (x+10)/2 = 5.5 which is more than z

simillarly using II) if x = 1 and z=5 then (x+10)/2 = 5.5 which is more than z

and if x = 3 and z=15 then (x+10)/2 = 6.5 which is less than z

but if we combine the both

z is greater than (x+10)/2

So the answer is C.
_________________

hey ya......

Manager
Manager
avatar
Joined: 30 Aug 2005
Posts: 186
Followers: 1

Kudos [?]: 13 [0], given: 0

 [#permalink]

Show Tags

New post 08 Nov 2005, 06:05
Nakib,
Looks like you are leaving out the fact that z is closer to 10 than to x.
SVP
SVP
User avatar
Joined: 24 Sep 2005
Posts: 1890
Followers: 18

Kudos [?]: 245 [0], given: 0

Re: number line problem [#permalink]

Show Tags

New post 08 Nov 2005, 06:12
rianah100 wrote:
This one is from GMATPREP as well.
DS:

If x<10 and n is a positive integer, is z>(x+10)/2? (average of x and 10)

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

I am getting (D) as answer because (1) seems to be good enough info to conclude that z>(x+10)/2. Ofcourse, it is clear that (2) is ok too. But the answer is B.

Thanks!


uhm, the bold part is easily misunderstood ....some can understand that z is closer to 10 than to x ...others may think: z is closer to 10 than x is . IMO, it is the latter one :?: . They are totally different and thus lead to completely different outcomes.
SVP
SVP
User avatar
Joined: 28 May 2005
Posts: 1723
Location: Dhaka
Followers: 7

Kudos [?]: 224 [0], given: 0

 [#permalink]

Show Tags

New post 08 Nov 2005, 06:17
rianah100 wrote:
Nakib,
Looks like you are leaving out the fact that z is closer to 10 than to x.


If z is closer to 10 than to x, then answer will be obviously D.

but If z is closer to 10 than x, the answer will be C.
_________________

hey ya......

Intern
Intern
avatar
Joined: 30 Sep 2005
Posts: 20
Followers: 0

Kudos [?]: 1 [0], given: 0

 [#permalink]

Show Tags

New post 08 Nov 2005, 07:27
I'm getting totally another answer: E

Number picking:

1 and 2 alone are clearly not sufficient.

But BOTH TOGETHER are also not sufficient:

x=1, z=5 (z closer to 10 and z = 5x) -> 5 < 5.5

BUT x=3, z=15 (conditions are also fullfilled) -> 15 > 6.5

It's not told that z < 10!!!

-> E
_________________

Looking for study partners:

http://www.gmatclub.com/phpbb/viewtopic.php?t=20834

SVP
SVP
User avatar
Joined: 24 Sep 2005
Posts: 1890
Followers: 18

Kudos [?]: 245 [0], given: 0

 [#permalink]

Show Tags

New post 08 Nov 2005, 07:43
lazy_k wrote:
I'm getting totally another answer: E

Number picking:

1 and 2 alone are clearly not sufficient.

But BOTH TOGETHER are also not sufficient:

x=1, z=5 (z closer to 10 and z = 5x) -> 5 < 5.5

BUT x=3, z=15 (conditions are also fullfilled) -> 15 > 6.5

It's not told that z < 10!!!

-> E


in which way do you understand statement 1?!! ...uhm, I'm not sure with the statement as my above post pointed out why ..
Intern
Intern
avatar
Joined: 30 Sep 2005
Posts: 20
Followers: 0

Kudos [?]: 1 [0], given: 0

 [#permalink]

Show Tags

New post 08 Nov 2005, 07:55
I understand it in the way, that z is closer to 10 as x IS... (10-z < 10-x)
_________________

Looking for study partners:

http://www.gmatclub.com/phpbb/viewtopic.php?t=20834

Current Student
User avatar
Joined: 23 Oct 2005
Posts: 243
Schools: Cranfield SOM
Followers: 2

Kudos [?]: 13 [0], given: 2

Re: number line problem [#permalink]

Show Tags

New post 08 Nov 2005, 11:37
rianah100 wrote:
This one is from GMATPREP as well.
DS:

If x<10 and n is a positive integer, is z>(x+10)/2? (average of x and 10)

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

I am getting (D) as answer because (1) seems to be good enough info to conclude that z>(x+10)/2. Ofcourse, it is clear that (2) is ok too. But the answer is B.

Thanks!


I don't know why there is an 'n' in the stem. Anyway.. I got B.

(1) assume x = 8, z = 8.1.
(x+10)/2 = 9
Hence z < (x+10)/2

If x = 1 and z is 8.
z > (x+10)/2
since (x +10)/2 = 5.5.

so insuff.

(2) If z = 5x

stem can be is 5x > (x+10)/2
which is 5x > x/2 + 5 which is always true.

Hence B answers the Q.
Senior Manager
Senior Manager
User avatar
Joined: 19 Nov 2007
Posts: 470
Followers: 3

Kudos [?]: 158 [0], given: 4

GMAT ToolKit User
Re: number line problem [#permalink]

Show Tags

New post 29 Apr 2010, 16:08
If x = 1, z = 5, answer to the question is NO.
If x= 4, z = 20, answer to the question is YES.

Why is the answer B?
_________________

-Underline your question. It takes only a few seconds!
-Search before you post.

Expert Post
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 34112
Followers: 6106

Kudos [?]: 76902 [0], given: 9992

Re: number line problem [#permalink]

Show Tags

New post 30 Apr 2010, 10:01
Expert's post
5
This post was
BOOKMARKED
vscid wrote:
If x = 1, z = 5, answer to the question is NO.
If x= 4, z = 20, answer to the question is YES.

Why is the answer B?


Edited the question. the original question is below:

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

Given: \(0<x<10\).
Q: is z greater than the average of x and 10? Or: is \(z>\frac{10+x}{2}\)? --> \(2z>10+x\)?

(1) On the number line, z is closer to 10 than it is to x --> \(|10-z|<|z-x|\) --> as z is closer to 10 than it is to x, then z>x, so \(|z-x|=z-x\) --> two cases for 10-z:

A. \(z<10\) --> \(|10-z|=10-z\) --> \(|10-z|<|z-x|\) becomes: \(10-z<z-x\) --> \(2z>10+x\). Answer to the question YES.

B. \(z\geq{10}\) --> \(|10-z|=z-10\) --> \(|10-z|<|z-x|\) becomes: \(z-10<z-x\) --> \(z>10\) --> now, as \(z>10\), then \(2z>20\) and as \(x<10\), then \(x+10<20\), hence \(2z>10+x\). Answer to the question YES.

OR another approach:
Given:
x-----average-----10----- (average of x and 10 halfway between x and 10).

Now, as z is closer to 10 than it (z) is to x, then z is either in the blue area, so more than average OR in the green area, so also more than average. Answer to the question YES.

Sufficient.

(2) z = 5x --> is \(2z>10+x\)? --> is \(10x>10+x\)? --> is \(x>\frac{10}{9}\). We don't now that. Not sufficient. (we've gotten that if \(x>\frac{10}{9}\), then the answer to the question is YES, but if \(0<x\leq{\frac{10}{9}}\), then the answer to the question is NO.)

Answer: A.
_________________

New to the Math Forum?
Please read this: All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Intern
Intern
User avatar
Joined: 10 Jul 2010
Posts: 44
Followers: 0

Kudos [?]: 4 [0], given: 34

Re: number line problem [#permalink]

Show Tags

New post 22 Oct 2010, 21:53
A it is.. :)
GMAT Club Legend
GMAT Club Legend
User avatar
Joined: 09 Sep 2013
Posts: 10666
Followers: 496

Kudos [?]: 131 [0], given: 0

Premium Member
Re: This one is from GMATPREP as well. DS: If x<10 and n is a [#permalink]

Show Tags

New post 15 Oct 2013, 14:05
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.
_________________

GMAT Books | GMAT Club Tests | Best Prices on GMAT Courses | GMAT Mobile App | Math Resources | Verbal Resources

GMAT Club Legend
GMAT Club Legend
User avatar
Joined: 09 Sep 2013
Posts: 10666
Followers: 496

Kudos [?]: 131 [0], given: 0

Premium Member
Re: If x is a positive number less than 10, is z greater than th [#permalink]

Show Tags

New post 10 Feb 2015, 04:56
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.
_________________

GMAT Books | GMAT Club Tests | Best Prices on GMAT Courses | GMAT Mobile App | Math Resources | Verbal Resources

Intern
Intern
avatar
Joined: 07 Sep 2014
Posts: 16
Location: United States
GMAT Date: 03-14-2015
Followers: 0

Kudos [?]: 18 [0], given: 132

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

Show Tags

New post 11 Feb 2015, 05:07
rianah100 wrote:
This one is from GMATPREP as well.
DS:

If x<10 and n is a positive integer, is z>(x+10)/2? (average of x and 10)

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

I am getting (D) as answer because (1) seems to be good enough info to conclude that z>(x+10)/2. Ofcourse, it is clear that (2) is ok too. But the answer is B.

Thanks!

MODERATOR: EDITED THE QUESTION.

ORIGINAL QUESTION:


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

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

(2) z = 5x




Here's my take

the question simply asks that
is z>than the midpoint of x and 10

stated in the stem: x<10

STATEMENT 1) On the number line, z is closer to 10 than it is to x.

M-midpint
case1
---------------------X----------M--z------10--------------------

case 2
---------------------X----------M---------10---z-----------------

In any of the case z is greater than the midpoint as it is closer to 10 than x
and
if it is on the midpoint then it is at equal distance from x and 10.

so SUFFICIENT.

STATEMENT 2) z=5x

if X=1 then Z=5 but average of x and 10=5.5
so Z<(X+10)/2 :NO

if X=4 then Z=20 but average of x and 10=7
so Z>(X+10)/2 :YES

so NOT SUFFICIENT.

ANSWER A

:-D
Intern
Intern
avatar
Joined: 05 Dec 2013
Posts: 3
Followers: 0

Kudos [?]: 1 [0], given: 0

GMAT ToolKit User
Re: If x is a positive number less than 10, is z greater than th [#permalink]

Show Tags

New post 24 Feb 2015, 12:27
Please help me with statement (1). If x=8, and z=9, which z is closer to 10 on the number line, then 2(9)= 8 + 20.... So answer is "no". Every other scenarios make 2(z) > x+10 as "yes".... So I got this statement as Insufficient. What did I do wrong? Thanks.

Image Posted from GMAT ToolKit
Expert Post
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 34112
Followers: 6106

Kudos [?]: 76902 [0], given: 9992

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

Show Tags

New post 24 Feb 2015, 12:32
Expert's post
freesoybean wrote:
Please help me with statement (1). If x=8, and z=9, which z is closer to 10 on the number line, then 2(9)= 8 + 20.... So answer is "no". Every other scenarios make 2(z) > x+10 as "yes".... So I got this statement as Insufficient. What did I do wrong? Thanks.

Image Posted from GMAT ToolKit




If x = 8 and z = 9, then z = 9 is NOT closer to 10 than it (z) is it x = 8. 9 is exactly in the middle of 8 and 10.
_________________

New to the Math Forum?
Please read this: All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

GMAT Club Legend
GMAT Club Legend
User avatar
Joined: 09 Sep 2013
Posts: 10666
Followers: 496

Kudos [?]: 131 [0], given: 0

Premium Member
Re: If x is a positive number less than 10, is z greater than th [#permalink]

Show Tags

New post 06 Jun 2016, 07:35
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.
_________________

GMAT Books | GMAT Club Tests | Best Prices on GMAT Courses | GMAT Mobile App | Math Resources | Verbal Resources

Re: If x is a positive number less than 10, is z greater than th   [#permalink] 06 Jun 2016, 07:35
    Similar topics Author Replies Last post
Similar
Topics:
22 Experts publish their posts in the topic If x is a positive number less than 10, is z greater than th Bunuel 8 20 Feb 2014, 01:15
8 Experts publish their posts in the topic If x is a positive number less than 10, is z less than the metallicafan 16 25 Apr 2012, 11:22
12 Experts publish their posts in the topic If x is a positive integer less than 10, is z greater than enigma123 8 24 Feb 2012, 16:50
4 Experts publish their posts in the topic If a is a positive number less than 10, is c greater than rxs0005 8 02 Dec 2010, 03:27
51 Experts publish their posts in the topic If x is a positive number less than 10, is z greater than amitgovin 25 08 Nov 2009, 21:32
Display posts from previous: Sort by

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

  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 and phpBB SEO

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®.