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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 ## Arithmetic- roots tagged by: BTGmoderatorRO ##### This topic has 1 expert reply and 0 member replies ## Arithmetic- roots $$\sqrt{\left[\left(4.9\right)\cdot\left(10^9\right)\right]}\ is\ closest\ to\ which\ of\ the\ following?$$ A. 7,000 B. 70,000 C. 14,000 D. 22,000 E. 220,000 what is the correct approach to use here? My headache is getting higher with this question Thanks? ### GMAT/MBA Expert GMAT Instructor Joined 04 Oct 2017 Posted: 551 messages Followed by: 11 members Upvotes: 180 Quote: $$\sqrt{\left[\left(4.9\right)\cdot\left(10^9\right)\right]}\ is\ closest\ to\ which\ of\ the\ following?$$ A. 7,000 B. 70,000 C. 14,000 D. 22,000 E. 220,000 Hi Roland2rule, Let's take a look at your question. $$\sqrt{\left(4.9\right)\times10^9}$$ Let's write 10^9 as 10 * 10^8, we actually want to eliminate the decimal point from 4.9 $$=\sqrt{4.9\times10\times10^8}$$ $$=\sqrt{49\times10^8}$$ $$=\sqrt{49}\times\sqrt{10^8}$$ $$=7\times\sqrt{10^8}$$ $$=7\times\sqrt{\left(10^4\right)^2}$$ $$=7\times10^4$$ $$=70,000$$ Therefore, Option B is correct. Hope it helps. I am available if you'd like any follow up. _________________ 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 Study Smarter, Not Harder Available with Beat the GMAT members only code • Magoosh Study with Magoosh GMAT prep Available with Beat the GMAT members only code • FREE GMAT Exam Know how you'd score today for$0

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