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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 At Supersonic Corporation, the time required for a machine tagged by: BTGmoderatorLU This topic has 1 member reply Top Member At Supersonic Corporation, the time required for a machine Timer 00:00 Your Answer A B C D E Global Stats Difficult Source: Manhattan Prep At Supersonic Corporation, the time required to complete a job is determined by the formula: $$t=\sqrt{w}+\sqrt{(w-1)},$$ where w = the weight of the machine in pounds and t = the hours required to complete the job. If machine A weighs 8 pounds, and machine B weighs 7 pounds, how many hours will it take the two machines to finish one job if they work together? $$\text{A. }\frac{6}{7-\sqrt{3}}$$ $$\text{B. }\frac{1}{2}(\sqrt{8}+\sqrt{6})$$ $$\text{C. }\frac{1}{3}(6-\sqrt{3})$$ $$\text{D. }3(\sqrt{3}+\sqrt{2})$$ $$\text{E. }\sqrt{8}+2\sqrt{7}+\sqrt{6}$$ The OA is B Top Member Junior | Next Rank: 30 Posts Joined 03 Oct 2018 Posted: 10 messages t1= $$\sqrt{8}+\sqrt{7}\$$ t2= $$\sqrt{7\ }+\sqrt{6}$$ 1/t=(1/t1)+(1/t2) Before plugging in the values, its more efficient to rationalize the values here itself. So t1 becomes $$\sqrt{8\ }-\sqrt{7}$$ and t2= $$\sqrt{7}-\sqrt{6}$$. t=1/ $$\sqrt{8}-\sqrt{6}$$ Now rationalizing this value we get t= $$\frac{\sqrt{8}+\sqrt{6}}{2}$$ • Free Practice Test & Review How would you score if you took the GMAT 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 • Award-winning private GMAT tutoring Register now and save up to$200

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