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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 ## 700+ Question ##### This topic has 2 expert replies and 3 member replies ## 700+ Question Kim finds a 1-meter tree branch and marks it off in thirds and fifths. She then breaks the branch along all the markings and removes one piece of every distinct length. What fraction of the original branch remains? 2/5 7/15 1/2 8/15 3/5 OA 3/5 Master | Next Rank: 500 Posts Joined 11 Jun 2011 Posted: 370 messages Followed by: 2 members Upvotes: 27 Test Date: Late November Target GMAT Score: 700+ The answer is 3/5. You mark the pieces at 1/5ths and 1/3rds. You get portions of 20% 40% 60% 80% 100%, by 1/5th Markings. and 33.33% 66.66 % and 100%, by 1/3rd markings.(Both on the same branch of course) now you cut it at these portions: You get 20% piece(at 1st 15th marking) then 13.33 % piece(at first 1/3rd marking) and 6.77% piece.(at second 1/5th marking) All the remaining portions repeat the trend. You can better explain the problem to yourself by drawing it on your note! The remaining is from 40% to 100%= 60% of the original branch. Hence, 3/5. ### GMAT/MBA Expert GMAT Instructor Joined 03 Jul 2008 Posted: 1031 messages Followed by: 253 members Upvotes: 716 GMAT Score: 750 Another great explanation, Winnie! Just one more way to look at this - since they give it to you in fractions and the answers are in fractions, I'd look at this as a common denominator problem. You have markings each 1/5 and 1/3, or every 3/15 and 5/15. So you have markings at: 0, 5/15, 10/15, 1 0, 3/15, 6/15, 9/15, 12/15, 1 And since it's all common denominators you're at: 0, 3, 5, 6, 9, 10, 12, 1 So you have unique distances of 3, 2, and 1, so you'd remove 6 out of 15, having 9/15 or 3/5 left. Just since you see that they're already using fractions to start it's not a bad idea to try finding common denominators...then you're only dealing with the integer numerators making the math pretty quick. _________________ Brian Galvin GMAT Instructor Director of Academic Programs Veritas Prep Looking for GMAT practice questions? Try out the Veritas Prep Question Bank. Learn More. Enroll in a Veritas Prep GMAT class completely for FREE. Wondering if a GMAT course is right for you? Attend the first class session of an actual GMAT course, either in-person or live online, and see for yourself why so many students choose to work with Veritas Prep. Find a class now! ### GMAT/MBA Expert GMAT Instructor Joined 25 May 2010 Posted: 15381 messages Followed by: 1872 members Upvotes: 13060 GMAT Score: 790 chaitanya.mehrotra wrote: Kim finds a 1-meter tree branch and marks it off in thirds and fifths. She then breaks the branch along all the markings and removes one piece of every distinct length. What fraction of the original branch remains? 2/5 7/15 1/2 8/15 3/5 OA 3/5 Ignore the given length of 1-meter. The problem can be solved using any length. Let length = 15 meters. Dividing 15 into 3rds will yield markings at 5 and 10. Dividing 15 into 5ths will yield markings at 3,6,9, and 12. Listing the markings in order: 0......3....5..6......9..10....12......15 There are only 3 distinct lengths: 1 meter, 2 meters, and 3 meters. Subtracting these 3 distinct lengths from 15, we get: Length remaining = 15-1-2-3 = 9. Remaining length/Total length = 9/15 = 3/5. _________________ 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 Last edited by GMATGuruNY on Thu Jul 28, 2011 8:38 am; edited 2 times in total 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. Newbie | Next Rank: 10 Posts Joined 26 Jul 2011 Posted: 5 messages In my opinion, numbers are easier to deal with as compared to fractions. Looking at the branch as a numberline and taking the length at 100cm the thirds markings will be at 33.33 and 66.66 The fifths markings will be at 20, 40, 60, 80 Arranging them on the number line gives us 20, 33.33, 40, 60, 66.66, 80, 100 So the lengths of the pieces would be 20, 13.33, 6.66, 20, 6.66, 13.33, 20 Picking out each distinct length takes out 6.66+13.33+20 40. What remains is 100-40 = 60. Hence 3/5. Senior | Next Rank: 100 Posts Joined 29 Nov 2009 Posted: 54 messages Upvotes: 4 Test Date: Not Decided Target GMAT Score: 750 GMAT Score: N.A • 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 GMAT Exam Know how you'd score today for$0

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