Jun 29 07:00 AM PDT  09:00 AM PDT Learn reading strategies that can help even nonvoracious reader to master GMAT RC Jun 30 07:00 AM PDT  09:00 AM PDT Get personalized insights on how to achieve your Target Quant Score. Jul 01 08:00 AM PDT  09:00 AM PDT Game of Timers is a teambased competition based on solving GMAT questions to win epic prizes! Starting July 1st, compete to win prep materials while studying for GMAT! Registration is Open! Jul 01 10:00 PM PDT  11:00 PM PDT Join a FREE 1day workshop and learn how to ace the GMAT while keeping your fulltime job. Limited for the first 99 registrants.
Author 
Message 
TAGS:

Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 55804

Positive integer y is 50 percent of 50 percent of positive
[#permalink]
Show Tags
02 Jul 2012, 02:05
Question Stats:
79% (01:51) correct 21% (02:08) wrong based on 1237 sessions
HideShow timer Statistics
The Official Guide for GMAT® Review, 13th Edition  Quantitative Questions ProjectPositive integer y is 50 percent of 50 percent of positive integer x, and y percent of x equals 100. What is the value of x? (A) 50 (B) 100 (C) 200 (D) 1,000 (E) 2,000 Diagnostic Test Question: 12 Page: 22 Difficulty: 650 GMAT Club is introducing a new project: The Official Guide for GMAT® Review, 13th Edition  Quantitative Questions ProjectEach week we'll be posting several questions from The Official Guide for GMAT® Review, 13th Edition and then after couple of days we'll provide Official Answer (OA) to them along with a slution. We'll be glad if you participate in development of this project: 1. Please provide your solutions to the questions; 2. Please vote for the best solutions by pressing Kudos button; 3. Please vote for the questions themselves by pressing Kudos button; 4. Please share your views on difficulty level of the questions, so that we have most precise evaluation. Thank you!
Official Answer and Stats are available only to registered users. Register/ Login.
_________________




SVP
Status: The Best Or Nothing
Joined: 27 Dec 2012
Posts: 1787
Location: India
Concentration: General Management, Technology
WE: Information Technology (Computer Software)

Positive integer y is 50 percent of 50 percent of positive integ
[#permalink]
Show Tags
02 Apr 2014, 02:32
\(y = \frac{50x}{100} * \frac{50}{100}\) \(y = \frac{25x}{100}\) .......... (1) \(\frac{xy}{100} = 100\) \(y = 100 * \frac{100}{x}\) ..... (2) Equating (1) & (2) \(\frac{25x}{100} = 100 * \frac{100}{x}\) \(25 x^2 = 100 * 100 * 100\) \(x^2 = 4 * 100 * 100\) x = 2 * 10 * 10 = 200 Answer = C
_________________
Kindly press "+1 Kudos" to appreciate




Math Expert
Joined: 02 Sep 2009
Posts: 55804

Re: Positive integer y is 50 percent of 50 percent of positive
[#permalink]
Show Tags
02 Jul 2012, 02:05
SOLUTIONPositive integer y is 50 percent of 50 percent of positive integer x, and y percent of x equals 100. What is the value of x?(A) 50 (B) 100 (C) 200 (D) 1,000 (E) 2,000 Given: \(x>0\) and \(y>0\). "Positive integer y is 50 percent of 50 percent of positive integer x" > \(y=0.5*(0.5x)=0.25x\); "y percent of x equals 100" > \(\frac{y}{100}*x=100\) > \(xy=100*100\) > substitute \(y\) > \(x^2=4*100*100\) > as \(x>0\), only one solution \(x=200\). Answer: C.
_________________



Director
Joined: 22 Mar 2011
Posts: 600
WE: Science (Education)

Re: Positive integer y is 50 percent of 50 percent of positive
[#permalink]
Show Tags
02 Jul 2012, 02:59
Bunuel wrote: The Official Guide for GMAT® Review, 13th Edition  Quantitative Questions ProjectPositive integer y is 50 percent of 50 percent of positive integer x, and y percent of x equals 100. What is the value of x? (A) 50 (B) 100 (C) 200 (D) 1,000 (E) 2,000 Diagnostic Test Question: 12 Page: 22 Difficulty: 650 GMAT Club is introducing a new project: The Official Guide for GMAT® Review, 13th Edition  Quantitative Questions ProjectEach week we'll be posting several questions from The Official Guide for GMAT® Review, 13th Edition and then after couple of days we'll provide Official Answer (OA) to them along with a slution. We'll be glad if you participate in development of this project: 1. Please provide your solutions to the questions; 2. Please vote for the best solutions by pressing Kudos button; 3. Please vote for the questions themselves by pressing Kudos button; 4. Please share your views on difficulty level of the questions, so that we have most precise evaluation. Thank you! The first information can be rewritten as \(y=0.5*0.5x=0.25x=\frac{x}{4}\), while the second information can be translated into \(\frac{y}{100}x=100\). If we substitute y from the first equation into the second one, we get \(\frac{x}{400}x=100\), from which \(x^2=400*100\), or \(x=\sqr{400*100}=\sqr{400}*\sqr{100}=20*10=200\). Answer: C
_________________
PhD in Applied Mathematics Love GMAT Quant questions and running.



Intern
Joined: 11 Mar 2013
Posts: 6

Re: Positive integer y is 50 percent of 50 percent of positive
[#permalink]
Show Tags
30 Jun 2015, 03:45
I need help understanding a pretty basic bit of substitution in the first explanation (I'm tired!). How do you jump from xy = 100 x 100 to x^2 = 4 x 100 x 100?
Thanks



Math Expert
Joined: 02 Sep 2009
Posts: 55804

Re: Positive integer y is 50 percent of 50 percent of positive
[#permalink]
Show Tags
30 Jun 2015, 03:50
jackrim1 wrote: I need help understanding a pretty basic bit of substitution in the first explanation (I'm tired!). How do you jump from xy = 100 x 100 to x^2 = 4 x 100 x 100?
Thanks \(xy=100*100\) and \(y=0.25x=\frac{x}{4}\); \(x*\frac{x}{4}=100*100\); \(x^2=4*100*100\). Hope it's clear.
_________________



Intern
Joined: 11 Mar 2013
Posts: 6

Re: Positive integer y is 50 percent of 50 percent of positive
[#permalink]
Show Tags
30 Jun 2015, 05:14
BunuelAh, of course, I must be having one of those days! thanks



Senior Manager
Joined: 20 Aug 2015
Posts: 388
Location: India

Re: Positive integer y is 50 percent of 50 percent of positive
[#permalink]
Show Tags
10 Dec 2015, 06:54
zz0vlb wrote: Positive integer y is 50 percent of 50 percent of positive integer x, and y percent of x equals 100. what is the value of x ?
A) 50 B) 100 C) 200 D) 1000 E) 2000
Given: x >0 and y > 0 y = \(\frac{50}{100}\)(\(\frac{50}{100}\)*x) = 0.25x  (i) \(\frac{y}{100}\)*x = 100. Hence xy = 10000  (ii) Required: Value of x Substituting the value of y in (ii) x*0.25x = 10000 \(x^2\) = 100*100*100/25 = 4*100*100 x = 200 and  200 We will consider only the positive value as we are told that x > 0 x = 200 Option C



Intern
Joined: 23 Dec 2015
Posts: 8

Re: Positive integer y is 50 percent of 50 percent of positive
[#permalink]
Show Tags
23 Dec 2015, 06:53
zz0vlb wrote: Positive integer y is 50 percent of 50 percent of positive integer x, and y percent of x equals 100. what is the value of x ? A) 50 B) 100 C) 200 D) 1000 E) 2000 y = 50% of 50% of x = (1/2)*(1/2)*x = x/4 (y/100)x=100 x^2/400 = 100 x = 200 IMO  C



EMPOWERgmat Instructor
Status: GMAT Assassin/CoFounder
Affiliations: EMPOWERgmat
Joined: 19 Dec 2014
Posts: 14403
Location: United States (CA)

Re: Positive integer y is 50 percent of 50 percent of positive
[#permalink]
Show Tags
26 Dec 2015, 09:41
Hi All, This question can be solved by TESTing THE ANSWERS. We're told that: 1) Positive integer Y is 50 percent of 50 percent of positive integer X 2) Y percent of X equals 100 We're asked for the value of X. Let's TEST Answer B: 100 IF.... X = 100 Y = (.5)(.5)(100) = 25 25% of 100 = 25 (but it's supposed to be 100). This answer is TOO SMALL. Let's TEST Answer D: 1000 IF.... X = 1000 Y = (.5)(.5)(1000) = 250 250% of 1000 = 2500 (but it's supposed to be 100). This answer is TOO BIG. The likely correct answer is C, but we can TEST it rather easily... IF.... X = 200 Y = (.5)(.5)(200) = 50 50% of 200 = 100. This is an exact MATCH for what we were told, so this MUST be the answer. Final Answer: GMAT assassins aren't born, they're made, Rich
_________________
760+: Learn What GMAT Assassins Do to Score at the Highest Levels Contact Rich at: Rich.C@empowergmat.com*****Select EMPOWERgmat Courses now include ALL 6 Official GMAC CATs!*****
Rich Cohen
CoFounder & GMAT Assassin
Special Offer: Save $75 + GMAT Club Tests Free
Official GMAT Exam Packs + 70 Pt. Improvement Guarantee www.empowergmat.com/



Retired Moderator
Joined: 19 Mar 2014
Posts: 929
Location: India
Concentration: Finance, Entrepreneurship
GPA: 3.5

Re: Positive integer y is 50 percent of 50 percent of positive
[#permalink]
Show Tags
26 Jun 2017, 06:54
Positive integer y is 50 percent of 50 percent of positive integer x, and y percent of x equals 100. what is the value of x ?\(y = \frac{50}{100} * \frac{50}{100} * x\) \(y Percent * x = 100\) \(\frac{y}{100} * x = 100\) \(x = \frac{(100 * 100)}{y}\) \(x = \frac{(100 * 100)}{(50/100) * (50/100) * x}\) \(x^2 =\frac{(100 * 100 * 100 * 100)}{(50 * 50)}\) \(x^2 = 40000\) \(x = 200\) (We are not taking other value of 200 as it is given that x is positive number) Hence, Answer is C
_________________
"Nothing in this world can take the place of persistence. Talent will not: nothing is more common than unsuccessful men with talent. Genius will not; unrewarded genius is almost a proverb. Education will not: the world is full of educated derelicts. Persistence and determination alone are omnipotent."
Best AWA Template: https://gmatclub.com/forum/howtoget60awamyguide64327.html#p470475



Target Test Prep Representative
Status: Founder & CEO
Affiliations: Target Test Prep
Joined: 14 Oct 2015
Posts: 6681
Location: United States (CA)

Re: Positive integer y is 50 percent of 50 percent of positive
[#permalink]
Show Tags
28 Jun 2017, 17:02
zz0vlb wrote: Positive integer y is 50 percent of 50 percent of positive integer x, and y percent of x equals 100. what is the value of x ?
A) 50 B) 100 C) 200 D) 1000 E) 2000 We can create the following equations: y = (0.5)(0.5)x y = 0.25x and (y/100)x = 100 Substitute y = 0.25x into the above equation: (0.25x/100)x = 100 0.25x^2 = 10,000 x^2 = 40,000 x = 200 Answer: C
_________________
5star rated online GMAT quant self study course See why Target Test Prep is the top rated GMAT quant course on GMAT Club. Read Our Reviews If you find one of my posts helpful, please take a moment to click on the "Kudos" button.



VP
Joined: 09 Mar 2016
Posts: 1274

Re: Positive integer y is 50 percent of 50 percent of positive
[#permalink]
Show Tags
09 Mar 2018, 11:01
Bunuel wrote: The Official Guide for GMAT® Review, 13th Edition  Quantitative Questions ProjectPositive integer y is 50 percent of 50 percent of positive integer x, and y percent of x equals 100. What is the value of x? (A) 50 (B) 100 (C) 200 (D) 1,000 (E) 2,000 Diagnostic Test Question: 12 Page: 22 Difficulty: 650 GMAT Club is introducing a new project: The Official Guide for GMAT® Review, 13th Edition  Quantitative Questions ProjectEach week we'll be posting several questions from The Official Guide for GMAT® Review, 13th Edition and then after couple of days we'll provide Official Answer (OA) to them along with a slution. We'll be glad if you participate in development of this project: 1. Please provide your solutions to the questions; 2. Please vote for the best solutions by pressing Kudos button; 3. Please vote for the questions themselves by pressing Kudos button; 4. Please share your views on difficulty level of the questions, so that we have most precise evaluation. Thank you! Hello everyone happy to see you all i think this problem can be solved logically if if y is 50 percent of 50 percent of positive integer x which implies that X is twice bigger number than y and if y percent of x equals 100  this means that 50 percent of 50 percent of positive integer x = 100 ( hence y = 100 and x = 200) y = .50 (200) = 100 it means that answer must be 200 options D and E are eliminated stright away because x can not be bigger number. likewise A and B are out cant be equal or smaller than 50% of x YAY



NonHuman User
Joined: 09 Sep 2013
Posts: 11449

Re: Positive integer y is 50 percent of 50 percent of positive
[#permalink]
Show Tags
14 Mar 2019, 06:55
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.
_________________




Re: Positive integer y is 50 percent of 50 percent of positive
[#permalink]
14 Mar 2019, 06:55






