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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 ## The average length of all the sides of a rectangle equals tagged by: M7MBA ##### This topic has 1 expert reply and 0 member replies ### Top Member ## The average length of all the sides of a rectangle equals The average length of all the sides of a rectangle equals twice the width of the rectangle. If the area of the rectangle is 18, what is its perimeter? $$(A)\ 6\sqrt{6}$$ $$(B)\ 8\sqrt{6}$$ $$(C)\ 24$$ $$(D)\ 32$$ $$(E)\ 48$$ The OA is B. What are the calculations behind this Ps question? Experts, could you show me how to determine the answer? ### GMAT/MBA Expert GMAT Instructor Joined 04 Oct 2017 Posted: 551 messages Followed by: 11 members Upvotes: 180 Hello M7MBA. Let's take a look at your question. We have the next rectangle: The area of the rectangle is 18, that is to say, $$x\cdot y=18.$$. Also, "the average length of all the sides of a rectangle equals twice the width of the rectangle" means $$\frac{x+y+x+y}{4}=\frac{2x+2y}{4}=\frac{x+y}{2}=2\cdot y.$$ We can rewrite this last equation as follows: $$x+y=4y\ <-->\ x=3y.$$ If we replace this last equation in the area equation we will get: $$x\cdot y=18<-->\ 3y\cdot y=18<-->y^2=6<-->\ y=\sqrt{6}.$$ This implies that $$x=3\sqrt{6}.$$ and the perimeter is equal to $$2x+2y=6\sqrt{6}+2\sqrt{6}=8\sqrt{6}.$$ So, the correct answer is B. I hope this can help you to understand the calculus. 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. • 5-Day Free Trial 5-day free, full-access trial TTP Quant Available with Beat the GMAT members only code • Free Trial & Practice Exam BEAT THE GMAT EXCLUSIVE 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 • Magoosh Study with Magoosh GMAT prep Available with Beat the GMAT members only code • Award-winning private GMAT tutoring Register now and save up to$200

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