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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 ## GMAT Official Guide 2019 (1/2 - 1/3) + (1/3-1/4) ##### This topic has 3 expert replies and 0 member replies ### Top Member ## GMAT Official Guide 2019 (1/2 - 1/3) + (1/3-1/4) ## Timer 00:00 ## Your Answer A B C D E ## Global Stats Difficult $$\left(\frac{1}{2}-\frac{1}{3}\right)+\left(\frac{1}{3}-\frac{1}{4}\right)+\left(\frac{1}{4}-\frac{1}{5}\right)+\left(\frac{1}{5}-\frac{1}{6}\right)=$$ $$A.\ -\frac{1}{6}$$ B. 0 $$C.\ \frac{1}{3}$$ $$D.\ \frac{1}{2}$$ $$E.\ \frac{2}{3}$$ ### GMAT/MBA Expert GMAT Instructor Joined 25 Apr 2015 Posted: 2244 messages Followed by: 17 members Upvotes: 43 Top Reply BTGmoderatorDC wrote: $$\left(\frac{1}{2}-\frac{1}{3}\right)+\left(\frac{1}{3}-\frac{1}{4}\right)+\left(\frac{1}{4}-\frac{1}{5}\right)+\left(\frac{1}{5}-\frac{1}{6}\right)=$$ $$A.\ -\frac{1}{6}$$ B. 0 $$C.\ \frac{1}{3}$$ $$D.\ \frac{1}{2}$$ $$E.\ \frac{2}{3}$$ If we remove the parentheses, it is easy to see that all the terms except the first and last are cancelled. So we are left with 1/2 - 1/6 = 3/6 - 1/6 = 2/6 = 1/3 Answer: C _________________ Scott Woodbury-Stewart Founder and CEO ### GMAT/MBA Expert Elite Legendary Member Joined 23 Jun 2013 Posted: 10112 messages Followed by: 494 members Upvotes: 2867 GMAT Score: 800 Top Reply Hi All, When a GMAT question presents what appears to be a 'step heavy' calculation to you, it's important to remember that the Quant section of the GMAT is NOT a 'math test'; it's a 'critical thinking' test that requires lots of little calculations as you work through it. Here, while it may be temping to try to perform each individual calculation, you should note the patterns involved in the work. Notice that while you 'subtract 1/3' early on, you would then 'ADD 1/3' in the next step, so those two calculations 'cancel out.' The same cancellation occurs with the two 1/4s and so on. Thus, you're ultimately left with 1/2 - 1/6.... 1/2 - 1/6 = 3/6 - 1/6 = 2/6 = 1/3 Final Answer: C GMAT assassins aren't born, they're made, Rich _________________ Contact Rich at Rich.C@empowergmat.com ### GMAT/MBA Expert GMAT Instructor Joined 25 May 2010 Posted: 15203 messages Followed by: 1861 members Upvotes: 13060 GMAT Score: 790 BTGmoderatorDC wrote: $$\left(\frac{1}{2}-\frac{1}{3}\right)+\left(\frac{1}{3}-\frac{1}{4}\right)+\left(\frac{1}{4}-\frac{1}{5}\right)+\left(\frac{1}{5}-\frac{1}{6}\right)=$$ $$A.\ -\frac{1}{6}$$ B. 0 $$C.\ \frac{1}{3}$$ $$D.\ \frac{1}{2}$$ $$E.\ \frac{2}{3}$$ All the values between the first term and the last term CANCEL OUT. If we subtract the last term from the first term, we get: $$\ \frac{1}{2}-\frac{1}{6}=\ \frac{3}{6}-\frac{1}{6}=\frac{2}{6} = \frac{1}{3}$$ The correct answer is C. _________________ 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. • 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 • Get 300+ Practice Questions 25 Video lessons and 6 Webinars for FREE Available with Beat the GMAT members only code • FREE GMAT Exam Know how you'd score today for$0

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