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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 ## Algebra tagged by: BTGmoderatorRO ##### This topic has 1 expert reply and 0 member replies ## Algebra Hugo lies on top of a building, throwing pennies straight down to the street below. The formula for the height, H, that a penny falls is H=Vt+5t2H=Vt+5t2, where V/is the original velocity o f the penny (how fast Hugo throws it when it leaves his hand) and t is equal to the time it takes to hit the ground. The building is 60 meters high, and Hugo throws the penny down at an initial speed of 20 meters per second. How long does it take for the penny to hit the ground? A. 2/5 seconds B. 1 second C. 2 seconds D. 5 seconds E. 6 seconds OA is c what is the approach to use to determine the accurate answer? Thanks for your prompt response ### GMAT/MBA Expert GMAT Instructor Joined 04 Oct 2017 Posted: 551 messages Followed by: 11 members Upvotes: 180 Quote: Hugo lies on top of a building, throwing pennies straight down to the street below. The formula for the height, H, that a penny falls is H=Vt+5t2H=Vt+5t2, where V/is the original velocity o f the penny (how fast Hugo throws it when it leaves his hand) and t is equal to the time it takes to hit the ground. The building is 60 meters high, and Hugo throws the penny down at an initial speed of 20 meters per second. How long does it take for the penny to hit the ground? A. 2/5 seconds B. 1 second C. 2 seconds D. 5 seconds E. 6 seconds OA is c Hi Roland2rule, Let's take a look at your question. The formula for the height H, that a penny falls is given by: $$H=vt+5t^2$$ The building is 60m high, It means $$H=60m$$ Initial speed of penny is given by 20m/s, therefore, $$v=20\ \frac{m}{s}$$ We are asked to find the time 't' the penny takes to hit the ground. Let's plugin all the given values in the formula of height. $$60=20t+5t^2$$ $$5t^2+20t-60=0$$ Factor out 5: $$5\left(t^2+4t-12\right)=0$$ $$t^2+4t-12=0$$ $$t^2+6t-2t-12=0$$ $$t\left(t+6\right)-2\left(t+6\right)=0$$ $$\left(t-2\right)\left(t+6\right)=0$$ $$\left(t-2\right)=0\ or\ \left(t+6\right)=0$$ $$t=2,\ -6$$ Since time can not be zero, therefore we will eliminate t = -6. Therefore, the penny will hit the ground in 2 seconds. Option C 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. • Magoosh Study with Magoosh GMAT prep 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 • Free Practice Test & Review How would you score if you took the GMAT Available with Beat the GMAT members only code • 1 Hour Free BEAT THE GMAT EXCLUSIVE 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 • Get 300+ Practice Questions 25 Video lessons and 6 Webinars for FREE Available with Beat the GMAT members only code • FREE GMAT Exam Know how you'd score today for$0

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