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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 ## Planifying the lateral surface area of a cone, we get the ci tagged by: fskilnik@GMATH ##### This topic has 1 expert reply and 0 member replies ### GMAT/MBA Expert ## Planifying the lateral surface area of a cone, we get the ci ## Timer 00:00 ## Your Answer A B C D E ## Global Stats Difficult GMATH practice exercise (Quant Class 11) Planifying the lateral surface area of a cone, we get the circular sector with center O and radius 18 shown in the figure. Which of the following is closest to the length of the height of this cone? (A) 12 (B) 14 (C) 16 (D) 18 (E) 20 Answer: ____(C)__ _________________ 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 11) Planifying the lateral surface area of a cone, we get the circular sector with center O and radius 18 shown in the figure. Which of the following is closest to the length of the height of this cone? (A) 12 (B) 14 (C) 16 (D) 18 (E) 20 $$?\,\, \cong \,\,h$$ $${\text{circular}}\,\,{\text{base}}\,{\text{of}}\,\,{\text{cone}}\,\,:\,\,\,\,2\pi r\,\, = \,\,\frac{{{{160}^ \circ }}}{{{{360}^ \circ }}}\left( {2\pi \cdot 18} \right)\,\,\,\,\, \Rightarrow \,\,\,\,\,r = \frac{{16 \cdot 18}}{{36}} = 8$$ $$\left( {{\text{Pythagoras}}} \right)\,\,\,\,{h^2} = {18^2} - {8^2} = \underleftrightarrow {\left( {18 - 8} \right)\left( {18 + 8} \right)} = 260$$ $${h^2} \cong 256 = {16^2}\,\,\,\,\,\mathop \Rightarrow \limits^{h\, > \,\,0} \,\,\,\,\,? = 16$$ The correct answer is (C). 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 Veritas GMAT Class Experience Lesson 1 Live Free Available with Beat the GMAT members only code • Free Trial & Practice Exam 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 Study Smarter, Not Harder Available with Beat the GMAT members only code • 1 Hour Free BEAT THE GMAT EXCLUSIVE 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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