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

It is currently 18 Oct 2018, 00:40

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

M09-19

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

Hide Tags

Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 49968
Re: M09-19  [#permalink]

Show Tags

New post 14 Nov 2017, 02:01
KungFuGmat wrote:
Hi Bunuel,

Many thanks for this great question. I got the solution, the way you showed it. Only today, while I was attempting another question from the GMAT Club tests, I stumbled upon the sign method for solving inequalities. I was just wondering if you or someone else could kindly explain how to solve THIS question using the sign method. Many thanks!


Can you please tell me what "sign method" are you referring to? Thank you.
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | 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

Manager
Manager
avatar
B
Joined: 15 Sep 2016
Posts: 73
Location: Pakistan
Concentration: Finance, Technology
Schools: CBS '20
GMAT 1: 640 Q43 V35
Reviews Badge
Re: M09-19  [#permalink]

Show Tags

New post 14 Nov 2017, 02:38
Bunuel,

Apologies if I got the name wrong. I just learnt about it today. Don't have strong handle on it.

The discussion is here:
https://gmatclub.com/forum/inequalities ... 91482.html
_________________

If you must err, err on the side of hope.
I believe in your success

Manager
Manager
avatar
B
Joined: 15 Sep 2016
Posts: 73
Location: Pakistan
Concentration: Finance, Technology
Schools: CBS '20
GMAT 1: 640 Q43 V35
Reviews Badge
Re: M09-19  [#permalink]

Show Tags

New post 14 Nov 2017, 02:57
I think VeritasPrepKarishma gave a detailed explanation on the process. Sorry, I am just learning it, so it's really rusty for me.
_________________

If you must err, err on the side of hope.
I believe in your success

Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 49968
Re: M09-19  [#permalink]

Show Tags

New post 14 Nov 2017, 03:03
KungFuGmat wrote:
I think VeritasPrepKarishma gave a detailed explanation on the process. Sorry, I am just learning it, so it's really rusty for me.


Check for more below links:

9. Inequalities



For more check Ultimate GMAT Quantitative Megathread



Hope it helps.
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | 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

Senior Manager
Senior Manager
avatar
P
Joined: 16 Nov 2016
Posts: 282
WE: Advertising (Advertising and PR)
GMAT ToolKit User Premium Member Reviews Badge CAT Tests
M09-19  [#permalink]

Show Tags

New post 19 Aug 2018, 23:12
Bunuel wrote:
Official Solution:


Is \(|x - 5| \gt 4\)?

Is \(|x-5| \gt 4\)? Opening the absolute value we get the question: is \(x \lt 1\) or \(x \gt 9\)?

(1) \(x^2-4 \lt 0\) and thus \(x^2 \lt 4\) therefore \(|x| \lt 2\) and we can deduce that \(-2 < x < 2\), so we can have an YES answer as well as a NO answer (consider \(x=0\) and \(x=1.5\)). Not sufficient.

(2) \(x^2-1 \lt 0\) thus \(x^2 \lt 1\) therefore \(|x| \lt 1\) and finally, \(-1 \lt x \lt 1\). Sufficient.


Answer: B


Hi Bunuel

if \(x^3 < 27\)

what will be the value of x?
_________________

If you find my post useful, please give me a kudos.

Thank you.
Regards,
ENEM

If you wish to spend wisely on your gmat prep material, check my post titled: How to Spend Money On GMAT Material Wisely, link: https://gmatclub.com/forum/how-to-buy-gmat-material-wisely-tag-free-gmat-resources-236174.html

Simple and handy template for CR: https://gmatclub.com/forum/simple-and-handy-template-for-cr-242255.html

simple template for more vs greater and fewer vs less: https://gmatclub.com/forum/simple-template-for-more-vs-greater-and-fewer-vs-less-242216.html

Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 49968
Re: M09-19  [#permalink]

Show Tags

New post 19 Aug 2018, 23:40
1
ENEM wrote:
Bunuel wrote:
Official Solution:


Is \(|x - 5| \gt 4\)?

Is \(|x-5| \gt 4\)? Opening the absolute value we get the question: is \(x \lt 1\) or \(x \gt 9\)?

(1) \(x^2-4 \lt 0\) and thus \(x^2 \lt 4\) therefore \(|x| \lt 2\) and we can deduce that \(-2 < x < 2\), so we can have an YES answer as well as a NO answer (consider \(x=0\) and \(x=1.5\)). Not sufficient.

(2) \(x^2-1 \lt 0\) thus \(x^2 \lt 1\) therefore \(|x| \lt 1\) and finally, \(-1 \lt x \lt 1\). Sufficient.


Answer: B


Hi Bunuel

if \(x^3 < 27\)

what will be the value of x?


Recall that we can always raise both parts of an inequality to an odd power and take an odd root of both sides of an inequality. So, by taking the third root from \(x^3 < 27\) we'll get x < 3.
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | 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

Senior Manager
Senior Manager
avatar
P
Joined: 16 Nov 2016
Posts: 282
WE: Advertising (Advertising and PR)
GMAT ToolKit User Premium Member Reviews Badge CAT Tests
Re: M09-19  [#permalink]

Show Tags

New post 20 Aug 2018, 03:24
[/quote]if \(x^3 < 27\)

what will be the value of x?[/quote]

Recall that we can always raise both parts of an inequality to an odd power and take an odd root of both sides of an inequality. So, by taking the third root from \(x^3 < 27\) we'll get x < 3.[/quote]

thank you Bunuel

and if \(x^3 < -27\)

then \(x < -3\)

is that correct?
_________________

If you find my post useful, please give me a kudos.

Thank you.
Regards,
ENEM

If you wish to spend wisely on your gmat prep material, check my post titled: How to Spend Money On GMAT Material Wisely, link: https://gmatclub.com/forum/how-to-buy-gmat-material-wisely-tag-free-gmat-resources-236174.html

Simple and handy template for CR: https://gmatclub.com/forum/simple-and-handy-template-for-cr-242255.html

simple template for more vs greater and fewer vs less: https://gmatclub.com/forum/simple-template-for-more-vs-greater-and-fewer-vs-less-242216.html

Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 49968
Re: M09-19  [#permalink]

Show Tags

New post 20 Aug 2018, 03:55
1
ENEM wrote:
if \(x^3 < 27\)

what will be the value of x?[/quote]

Recall that we can always raise both parts of an inequality to an odd power and take an odd root of both sides of an inequality. So, by taking the third root from \(x^3 < 27\) we'll get x < 3.[/quote]

thank you Bunuel

and if \(x^3 < -27\)

then \(x < -3\)

is that correct?[/quote]

Absolutely: recall that odd roots have the same sign as the base of the root, for example: \(\sqrt[3]{125} = 5\) and \(\sqrt[3]{-64} = -4\).
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | 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 Bot
Re: M09-19 &nbs [#permalink] 20 Aug 2018, 03:55

Go to page   Previous    1   2   [ 28 posts ] 

Display posts from previous: Sort by

M09-19

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  

Moderators: chetan2u, Bunuel



Copyright

GMAT Club MBA Forum Home| About| Terms and Conditions and Privacy Policy| 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®.