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

It is currently 12 Nov 2018, 16:38

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 in November
PrevNext
SuMoTuWeThFrSa
28293031123
45678910
11121314151617
18192021222324
2526272829301
Open Detailed Calendar
  • Essential GMAT Time-Management Hacks

     November 14, 2018

     November 14, 2018

     08:00 PM MST

     09:00 PM MST

    Join the webinar and learn time-management tactics that will guarantee you answer all questions, in all sections, on time. Save your spot today! Nov. 14th at 7 PM PST
  • $450 Tuition Credit & Official CAT Packs FREE

     November 15, 2018

     November 15, 2018

     10:00 PM MST

     11:00 PM MST

    EMPOWERgmat is giving away the complete Official GMAT Exam Pack collection worth $100 with the 3 Month Pack ($299)

M21-14

  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: 50544
M21-14  [#permalink]

Show Tags

New post 16 Sep 2014, 00:10
00:00
A
B
C
D
E

Difficulty:

  55% (hard)

Question Stats:

58% (01:14) correct 42% (01:37) wrong based on 168 sessions

HideShow timer Statistics

Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 50544
Re M21-14  [#permalink]

Show Tags

New post 16 Sep 2014, 00:10
Official Solution:

What positive number is 224 percent greater than its reciprocal?

A. 0.8
B. 1.1
C. 1.5
D. 1.8
E. 2.2


We should find such \(x\) that satisfy the following equation: \(x=\frac{1}{x}+\frac{1}{x}*\frac{224}{100}\);

\(x=\frac{1}{x}*3.24\);

\(x^2=3.24\);

\(x=1.8\) (since give that \(x\) is a positive number).


Answer: D
_________________

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

Intern
Intern
avatar
B
Joined: 21 May 2013
Posts: 8
Re: M21-14  [#permalink]

Show Tags

New post 03 Oct 2014, 10:47
Bunuel wrote:
Official Solution:

What positive number is 224 percent greater than its reciprocal?

A. 0.8
B. 1.1
C. 1.5
D. 1.8
E. 2.2


We should find such \(x\) that satisfy the following equation: \(x=\frac{1}{x}+\frac{1}{x}*\frac{224}{100}\);

\(x=\frac{1}{x}*3.24\);

\(x^2=3.24\);

\(x=1.8\) (since give that \(x\) is a positive number).


Answer: D


Hi Bunuel,

Can you please explain how you got the 3.24 in the 2nd equation?

Thank you
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 50544
Re: M21-14  [#permalink]

Show Tags

New post 03 Oct 2014, 10:50
1
safaria25 wrote:
Bunuel wrote:
Official Solution:

What positive number is 224 percent greater than its reciprocal?

A. 0.8
B. 1.1
C. 1.5
D. 1.8
E. 2.2


We should find such \(x\) that satisfy the following equation: \(x=\frac{1}{x}+\frac{1}{x}*\frac{224}{100}\);

\(x=\frac{1}{x}*3.24\);

\(x^2=3.24\);

\(x=1.8\) (since give that \(x\) is a positive number).


Answer: D


Hi Bunuel,

Can you please explain how you got the 3.24 in the 2nd equation?

Thank you


\(x=\frac{1}{x}+\frac{1}{x}*\frac{224}{100}\);

\(x=\frac{1}{x}(1+\frac{224}{100}\);

\(x=\frac{1}{x}*3.24\).

Hope it's clear.
_________________

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
Joined: 14 Jul 2014
Posts: 93
Re: M21-14  [#permalink]

Show Tags

New post 11 Mar 2015, 20:26
Bunuel wrote:
Official Solution:

What positive number is 224 percent greater than its reciprocal?

A. 0.8
B. 1.1
C. 1.5
D. 1.8
E. 2.2


We should find such \(x\) that satisfy the following equation: \(x=\frac{1}{x}+\frac{1}{x}*\frac{224}{100}\);

\(x=\frac{1}{x}*3.24\);

\(x^2=3.24\);

\(x=1.8\) (since give that \(x\) is a positive number).


Answer: D



Brilliant way to solve this question !!!

I was manually backsolving by plugging in nos - Took ~ 3 Mins :(
Verbal Forum Moderator
avatar
Joined: 15 Apr 2013
Posts: 184
Location: India
Concentration: General Management, Marketing
GMAT Date: 11-23-2015
GPA: 3.6
WE: Science (Other)
GMAT ToolKit User Premium Member Reviews Badge
M21-14  [#permalink]

Show Tags

New post 11 Jul 2015, 04:59
Hello Bunnel,

Shouldn't be equation be written as

X = 1/X + X*224/100

Actually it is stated that "What positive number is 224 percent greater than its reciprocal

The point is, it is stated that 224% greater than its reciprocal but why we are taking 224% of reciprocal itself????

Looking for your response!

Please help.
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 50544
Re: M21-14  [#permalink]

Show Tags

New post 11 Jul 2015, 07:49
vikasbansal227 wrote:
Hello Bunnel,

Shouldn't be equation be written as

X = 1/X + X*224/100

Actually it is stated that "What positive number is 224 percent greater than its reciprocal

The point is, it is stated that 224% greater than its reciprocal but why we are taking 224% of reciprocal itself????

Looking for your response!

Please help.


1.8 is 224% greater than 1/1.8: http://www.wolframalpha.com/input/?i=1. ... an+1%2F1.8
_________________

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

Intern
Intern
avatar
B
Joined: 28 Dec 2015
Posts: 7
GMAT ToolKit User
Re: M21-14  [#permalink]

Show Tags

New post 02 Aug 2016, 07:02
according to the question (x-1/x)/(1/x) = 224/100. simplifying further we get x^2-1=224/100.
this implies x=1.8
Intern
Intern
avatar
Joined: 02 Sep 2016
Posts: 10
Re: M21-14  [#permalink]

Show Tags

New post 04 Oct 2016, 17:06
1
why is the equation=1/x +1/x*224/100 and not =1/x*224/100?
Senior Manager
Senior Manager
User avatar
S
Joined: 08 Jun 2015
Posts: 435
Location: India
GMAT 1: 640 Q48 V29
GMAT 2: 700 Q48 V38
GPA: 3.33
Premium Member
Re: M21-14  [#permalink]

Show Tags

New post 22 Nov 2017, 02:47
+1 for D. The number is 1.8. x=(3.24/x). i.e, x^2 = 3.24. x is 1.8
_________________

" The few , the fearless "

Intern
Intern
avatar
S
Joined: 31 Mar 2017
Posts: 35
GMAT 1: 710 Q45 V42
GMAT 2: 730 Q50 V39
GMAT 3: 740 Q50 V40
GPA: 3.73
M21-14  [#permalink]

Show Tags

New post 22 Nov 2017, 08:04
Convert 224% GREATER to algebraic expression
We know that 100% GREATER means X * 2 (twice as large)

Therefore 224% GREATER means X * 3.24

Based on this:
X = 1/X (3.24)

X^2 = 3.24

X must be between 1 and 2 so eliminate A and E

1.1 is unlikely. Eliminate B

1.5^2 = (3/2)^2 = 9/4...this is 2.25 so elim C

Answer must be D

To check: (9/5)^2 = 81/25 which is 3 and 6/25 = 3.24
Intern
Intern
avatar
B
Joined: 25 Jan 2017
Posts: 4
Re: M21-14  [#permalink]

Show Tags

New post 22 Nov 2017, 10:12
manchitkapoor wrote:
why is the equation=1/x +1/x*224/100 and not =1/x*224/100?


Because the question is asking for a number 224% greater than its reciprocal and not 224% of its reciprocal.
Intern
Intern
avatar
B
Joined: 30 Dec 2017
Posts: 12
Re: M21-14  [#permalink]

Show Tags

New post 04 Jan 2018, 18:32
Can someone explain why 224% greater is 3.24? I always thought 100% is twice, 200% is 4 times, so if 224%=~225% then it should be 4.5 times.
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 50544
Re: M21-14  [#permalink]

Show Tags

New post 04 Jan 2018, 19:32
KillerGMAT wrote:
Can someone explain why 224% greater is 3.24? I always thought 100% is twice, 200% is 4 times, so if 224%=~225% then it should be 4.5 times.


No. 100% more is *2 (1 + 1), 200% more is *3 (1 + 2), 300 more is *4 (1 + 3), ... 224% more is *(1 + 2.24) = *3.24.
_________________

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

Director
Director
User avatar
D
Joined: 11 Feb 2015
Posts: 558
Premium Member CAT Tests
M21-14  [#permalink]

Show Tags

New post 01 Nov 2018, 01:31
Whenever you have a positive number that is 224 percent greater than its reciprocal the paraphrase then stimulus in your words "i.e. a positive number is 3.24 times its reciprocal"...You will finish the question quickly!!
_________________

"Please hit :thumbup: +1 Kudos if you like this post" :student_man:

_________________
Manish :geek:

"Only I can change my life. No one can do it for me"

GMAT Club Bot
M21-14 &nbs [#permalink] 01 Nov 2018, 01:31
Display posts from previous: Sort by

M21-14

  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®.