• NEW! FREE Beat The GMAT Quizzes
Hundreds of Questions Highly Detailed Reporting Expert Explanations
• 7 CATs FREE!
If you earn 100 Forum Points

Engage in the Beat The GMAT forums to earn
100 points for $49 worth of Veritas practice GMATs FREE VERITAS PRACTICE GMAT EXAMS Earn 10 Points Per Post Earn 10 Points Per Thanks Earn 10 Points Per Upvote ## percent ##### This topic has 1 expert reply and 1 member reply ## percent ## Timer 00:00 ## Your Answer A B C D E ## Global Stats Difficult 50% of the apartments in a certain building have windows and hardwoods floors. 25% of the apartments without Windows have hardwood floors. If 40% of the apartments do not have hardwood floors, what percent of the apartments with Windows ha e hardwood floors? A 10% B 16.66% C 40% D 50% E 83.33% ### GMAT/MBA Expert GMAT Instructor Joined 25 Apr 2015 Posted: 1809 messages Followed by: 14 members Upvotes: 43 Top Reply vaibhav101 wrote: 50% of the apartments in a certain building have windows and hardwoods floors. 25% of the apartments without Windows have hardwood floors. If 40% of the apartments do not have hardwood floors, what percent of the apartments with Windows ha e hardwood floors? A 10% B 16.66% C 40% D 50% E 83.33% We can let the total number of apartments = 100. So, 50 have windows and hardwood floors. Since 40 do not have hardwood floors, then 60 do have hardwood floors. Thus, 60 - 50 = 10 have hardwood floors but no windows. We are given that 25% of the apartments without windows have hardwood floors and we found the number of such apartments is 10. If 25% of the apartments without windows is 10, the total number of apartments without windows is 10/0.25 = 40. Thus, there are 100 - 40 = 60 apartments that have windows. Since 50 of them have hardwood floors, 50/60 = â…š = 83.33% of them have hardwood floors. Answer: E _________________ Scott Woodbury-Stewart Founder and CEO ### Top Member Legendary Member Joined 02 Mar 2018 Posted: 786 messages Followed by: 1 members Top Reply Let a = total window b = total of apartment with no window. Apartment with window and hardwood floor = 50% $$=\ \frac{50}{100}=\ 0.5$$ $$Apartments\ without\ window\ bat\ have\ hardwood\ floor\ =25\%\ =\ \frac{25}{100\ }=\ 0.25$$ $$Apartments\ without\ hardwood\ floor\ =40\%\ =\ \frac{40}{100\ }=\ 0.4$$ Proportion of apartment with windows = a - b 1 - 0.4 = 0.6 $$\leftDesire\ proprtion\ =\ \frac{\left(Apartment\ with\ windows\ \&\ hardwood\ \right)}{total\ windows}\ \right\cdot\frac{100}{1}$$ $$=\ \frac{0.5}{0.6}\ \cdot\ \frac{100}{1}$$ = 83.33% Option E is CORRECT. • 5-Day Free Trial 5-day free, full-access trial TTP Quant Available with Beat the GMAT members only code • FREE GMAT Exam Know how you'd score today for$0

Available with Beat the GMAT members only code

• Free Veritas GMAT Class
Experience Lesson 1 Live Free

Available with Beat the GMAT members only code

• Free Practice Test & Review
How would you score if you took the GMAT

Available with Beat the GMAT members only code

• 1 Hour Free
BEAT THE GMAT EXCLUSIVE

Available with Beat the GMAT members only code

• Free Trial & Practice Exam
BEAT THE GMAT EXCLUSIVE

Available with Beat the GMAT members only code

• Get 300+ Practice Questions

Available with Beat the GMAT members only code

• Magoosh
Study with Magoosh GMAT prep

Available with Beat the GMAT members only code

• 5 Day FREE Trial
Study Smarter, Not Harder

Available with Beat the GMAT members only code

• Award-winning private GMAT tutoring
Register now and save up to \$200

Available with Beat the GMAT members only code

### Top First Responders*

1 Jay@ManhattanReview 67 first replies
2 Brent@GMATPrepNow 53 first replies
3 fskilnik@GMATH 49 first replies
4 GMATGuruNY 32 first replies
5 Rich.C@EMPOWERgma... 29 first replies
* Only counts replies to topics started in last 30 days
See More Top Beat The GMAT Members

### Most Active Experts

1 fskilnik@GMATH

GMATH Teacher

107 posts
2 Brent@GMATPrepNow

GMAT Prep Now Teacher

99 posts
3 Max@Math Revolution

Math Revolution

90 posts
4 Jay@ManhattanReview

Manhattan Review

78 posts
5 GMATGuruNY

The Princeton Review Teacher

77 posts
See More Top Beat The GMAT Experts