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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 ## If A>B are two odd numbers, how many even numbers are the tagged by: fskilnik@GMATH ##### This topic has 2 expert replies and 0 member replies ### GMAT/MBA Expert ## If A>B are two odd numbers, how many even numbers are the ## Timer 00:00 ## Your Answer A B C D E ## Global Stats Difficult GMATH practice exercise (Quant Class 16) If A>B are two odd numbers, how many even numbers are there between them? (A) (A+B)/2 (B) A-B+1 (C) A-B (D) A-B-1 (E) (A-B)/2 Answer: _____(E)__ _________________ Fabio Skilnik :: GMATH method creator ( Math for the GMAT) English-speakers :: https://www.gmath.net Portuguese-speakers :: https://www.gmath.com.br ### GMAT/MBA Expert GMAT Instructor Joined 09 Oct 2010 Posted: 1449 messages Followed by: 32 members Upvotes: 59 fskilnik@GMATH wrote: GMATH practice exercise (Quant Class 16) If A>B are two odd numbers, how many even numbers are there between them? (A) (A+B)/2 (B) A-B+1 (C) A-B (D) A-B-1 (E) (A-B)/2 $$?\,\, = \,\,\# \,\,{\rm{even}}\,\,{\rm{numbers}}\,\,{\rm{in}}\,\,\left[ {B,A} \right]\,\,\,\,\,\,\left( {B < A\,,\,\,{\rm{odds}}} \right)$$ First Approach ("the smart way"): $${\rm{Take}}\,\,\left( {B,A} \right) = \left( {1,5} \right)\,\,\,\,\, \Rightarrow \,\,\,\,\,{\rm{Target}} = 2\,\,\,\,\,\left[ {2,4} \right]$$ $$\left. \matrix{ \left( A \right)\,\,3\,\,\, \to \,\,\,{\rm{refuted}} \hfill \cr \left( B \right)\,\,5\,\,\, \to \,\,\,{\rm{refuted}} \hfill \cr \left( C \right)\,\,4\,\,\, \to \,\,\,{\rm{refuted}} \hfill \cr \left( D \right)\,\,3\,\,\, \to \,\,\,{\rm{refuted}}\,\,\, \hfill \cr} \right\}\,\,\,\,\, \Rightarrow \,\,\,\,\,\left( E \right)\,\,\,{\rm{by}}\,\,{\rm{exclusion}}$$ We follow the notations and rationale taught in the GMATH method. Regards, Fabio. _________________ Fabio Skilnik :: GMATH method creator ( Math for the GMAT) English-speakers :: https://www.gmath.net Portuguese-speakers :: https://www.gmath.com.br ### GMAT/MBA Expert GMAT Instructor Joined 09 Oct 2010 Posted: 1449 messages Followed by: 32 members Upvotes: 59 fskilnik@GMATH wrote: GMATH practice exercise (Quant Class 16) If A>B are two odd numbers, how many even numbers are there between them? (A) (A+B)/2 (B) A-B+1 (C) A-B (D) A-B-1 (E) (A-B)/2 $$?\,\, = \,\,\# \,\,{\rm{even}}\,\,{\rm{numbers}}\,\,{\rm{in}}\,\,\left[ {B,A} \right]\,\,\,\,\,\,\left( {B < A\,,\,\,{\rm{odds}}} \right)$$ Second Approach ("the technical way"): $$? = \# \,\,{\rm{even}}\,\,{\rm{numbers}}\,\,{\rm{in}}\,\,I = \left[ {B,A - 1} \right] = \,\,{1 \over 2}\left( {{\rm{\# }}\,\,{\rm{integers}}\,\,{\rm{in}}\,\,I} \right)$$ $$\left( {{\rm{\# }}\,\,{\rm{integers}}\,\,{\rm{in}}\,\,I} \right)\,\, = \,\,\left( {A - 1 - B} \right) + 1 = A - B\,\,\,\,\,\,\,\left[ {{\rm{fingers}}\,\,{\rm{technique}}} \right]$$ $$? = {{A - B} \over 2}$$ The correct answer is (E). We follow the notations and rationale taught in the GMATH method. Regards, Fabio. _________________ Fabio Skilnik :: GMATH method creator ( Math for the GMAT) English-speakers :: https://www.gmath.net Portuguese-speakers :: https://www.gmath.com.br • Free Trial & Practice Exam BEAT THE GMAT EXCLUSIVE 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 • 5-Day Free Trial 5-day free, full-access trial TTP Quant 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 • Free Practice Test & Review How would you score if you took the GMAT Available with Beat the GMAT members only code • Award-winning private GMAT tutoring Register now and save up to$200

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