• 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 ## A straight picket fence is composed of x pickets each of whi tagged by: rolandprowess ##### This topic has 3 expert replies and 0 member replies ## A straight picket fence is composed of x pickets each of whi A straight picket fence is composed of x pickets each of which is 1/2 inch wide. If there are 6 inches of space between each pair of pickets, which of the following represents the length of fence in feet? A. 13x/2 B. 13x/2 - 6 C. 13x/24 D. (13x+1)/24 E. (13x-12)/24 OA: E Need explanation why E is the correct answer? ### GMAT/MBA Expert GMAT Instructor Joined 25 May 2010 Posted: 15385 messages Followed by: 1872 members Upvotes: 13060 GMAT Score: 790 ardz24 wrote: A straight picket fence is composed of x pickets each of which is 1/2 inch wide. If there are 6 inches of space between each pair of pickets, which of the following represents the length of fence in feet? A. 13x/2 B. 13x/2 - 6 C. 13x/24 D. (13x+1)/24 E. (13x-12)/24 Let x=2, implying that there are only 2 pickets. Length of the 2 pickets = 2(1/2) = 1 inch. The space between them = 6 inches. Total length = 1+6 = 7 inches. Total length in feet = 7/12. This is our target. Now plug x=2 into the answers to see which yields our target of 7/12. Only E works: (13x-12)/24 = (13*2 - 12)/24 = 7/12. The correct answer is E. _________________ Mitch Hunt Private Tutor for the GMAT and GRE GMATGuruNY@gmail.com If you find one of my posts helpful, please take a moment to click on the "UPVOTE" icon. Available for tutoring in NYC and long-distance. For more information, please email me at GMATGuruNY@gmail.com. Student Review #1 Student Review #2 Student Review #3 Free GMAT Practice Test How can you improve your test score if you don't know your baseline score? Take a free online practice exam. Get started on achieving your dream score today! Sign up now. ### GMAT/MBA Expert Elite Legendary Member Joined 23 Jun 2013 Posted: 10197 messages Followed by: 497 members Upvotes: 2867 GMAT Score: 800 Hi ardz24, This is an example of a 'fence post' problem; they're relatively rare on the GMAT (you might not see any on Test Day). TESTing VALUES works perfectly here (as Mitch has shown), but sometimes these types of questions are about a specific calculation. The key to these types of questions is to realize that there is a 'post' at the beginning and the end of the 'row.' Here's a variation on that idea: if you read pages 2 through 5 (inclusive) of a book, then how many pages have you read? Many people would quickly say that the answer is 3 (since 5 - 2 = 3). However, that is NOT the correct answer. We have to include page 2 (it was one of the pages read; we read 2, 3, 4 and 5 - thus the total is 4 pages) so you have to go back and include that page after you subtract it. Thus, the answer is 5 - 2 + 1 = 4 GMAT assassins aren't born, they're made, Rich _________________ Contact Rich at Rich.C@empowergmat.com ### GMAT/MBA Expert GMAT Instructor Joined 04 Oct 2017 Posted: 551 messages Followed by: 11 members Upvotes: 180 Quote: A straight picket fence is composed of x pickets each of which is 1/2 inch wide. If there are 6 inches of space between each pair of pickets, which of the following represents the length of fence in feet? A. 13x/2 B. 13x/2 - 6 C. 13x/24 D. (13x+1)/24 E. (13x-12)/24 OA: E Need explanation why E is the correct answer? Hi ardz24, Let's take a look at your question. Since there are x pickets in the fence and each picket is 1/2 inch wide, so width of all x pickets will be (1/2)x Now, lets find the total gap between x pickets. If there are only 2 pickets, the gap between them is (2-1)(6) = (1)(6) = 6 inches If there are 3 pickets, the gap between them is (3-1)(6) = (2)(6) = 12 inches If there are 4 pickets, the gap between them is (4-1)(6) = (3)(6) = 18 inches ..... Similarly, If there are x pickets, the gap between them is (x-1)(6) = (6x-6) inches Total length of the fence in inches= width of x pickets + gap between x pickets $$=\frac{1}{2}x+\left(6x-6\right)$$ $$=\frac{1}{2}x+\frac{12}{2\ }x-6$$ $$=\frac{13}{2\ }x-6$$ We are asked to find the length of fence in feet. We know that, 1 foot = 12 inches and 1 inch = 1/12 foot, Therefore, Total length of the fence in feet = $$=\frac{1}{12}\left(\frac{13}{2\ }x-6\right)$$ $$=\frac{1}{12}\left(\frac{13x-12}{2\ }\right)$$ $$\left(\frac{13x-12}{24}\right)$$ Therefore, Option E is correct. I am available, if you'd like any follow up. _________________ GMAT Prep From The Economist We offer 70+ point score improvement money back guarantee. Our average student improves 98 points. Free 7-Day Test Prep with Economist GMAT Tutor - Receive free access to the top-rated GMAT prep course including a 1-on-1 strategy session, 2 full-length tests, and 5 ask-a-tutor messages. Get started now. • 5-Day Free Trial 5-day free, full-access trial TTP Quant Available with Beat the GMAT members only code • Magoosh Study with Magoosh GMAT prep 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

• Get 300+ Practice Questions

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 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

• Free Veritas GMAT Class
Experience Lesson 1 Live Free

Available with Beat the GMAT members only code

• 5 Day FREE Trial
Study Smarter, Not Harder

Available with Beat the GMAT members only code

### Top First Responders*

1 Ian Stewart 41 first replies
2 Brent@GMATPrepNow 36 first replies
3 Scott@TargetTestPrep 33 first replies
4 Jay@ManhattanReview 30 first replies
5 GMATGuruNY 23 first replies
* Only counts replies to topics started in last 30 days
See More Top Beat The GMAT Members

### Most Active Experts

1 Scott@TargetTestPrep

Target Test Prep

159 posts
2 Max@Math Revolution

Math Revolution

91 posts
3 Brent@GMATPrepNow

GMAT Prep Now Teacher

56 posts
4 Ian Stewart

GMATiX Teacher

50 posts
5 GMATGuruNY

The Princeton Review Teacher

35 posts
See More Top Beat The GMAT Experts