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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 ## For positive integer values of n, the operation . . . . . tagged by: Vincen ##### This topic has 1 expert reply and 0 member replies ### Top Member ## For positive integer values of n, the operation . . . . . For positive integer values of n, the operation n# is defined as the sum of all integers from 1 to n, inclusive. For example, 4# = 1 + 2 + 3 + 4 = 10. If 15# - 14# = k#, what is the value of k#? A. 1 B. 4 C. 5 D. 14 E. 15 The OA is the option E. Is there an easy way to solve this PS question without making the whole calculation? I need your help experts. Thanks in advanced. ### GMAT/MBA Expert GMAT Instructor Joined 04 Oct 2017 Posted: 551 messages Followed by: 11 members Upvotes: 180 Top Reply Hello Vincen. Let's take a look at your question. We have to solve 15#-14#=k#. But, we have to notice that 15# = 15 + 14#. Now, we can rewrite 15#-14#=k# as follows: $$k\# = 15\#-14\#\ =\ 15\ +\ 14\#\ -\ 14\#\ =\ 15 .$$ Therefore, the correct answer is E. I hope this explanation may help you. I'm available if you'd like a follow-up. Regards. _________________ 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. • Award-winning private GMAT tutoring Register now and save up to$200

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